sqlglot.executor.python API documentation

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# sqlglot.executor.python

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      1import ast
      2import collections
      3import itertools
      4import math
      5
      6from sqlglot import exp, generator, planner, tokens
      7from sqlglot.dialects.dialect import Dialect, inline_array_sql
      8from sqlglot.errors import ExecuteError
      9from sqlglot.executor.context import Context
     10from sqlglot.executor.env import ENV
     11from sqlglot.executor.table import RowReader, Table
     12from sqlglot.helper import csv_reader, subclasses
     13
     14
     15class PythonExecutor:
     16    def __init__(self, env=None, tables=None):
     17        self.generator = Python().generator(identify=True, comments=False)
     18        self.env = {**ENV, **(env or {})}
     19        self.tables = tables or {}
     20
     21    def execute(self, plan):
     22        finished = set()
     23        queue = set(plan.leaves)
     24        contexts = {}
     25
     26        while queue:
     27            node = queue.pop()
     28            try:
     29                context = self.context(
     30                    {
     31                        name: table
     32                        for dep in node.dependencies
     33                        for name, table in contexts[dep].tables.items()
     34                    }
     35                )
     36
     37                if isinstance(node, planner.Scan):
     38                    contexts[node] = self.scan(node, context)
     39                elif isinstance(node, planner.Aggregate):
     40                    contexts[node] = self.aggregate(node, context)
     41                elif isinstance(node, planner.Join):
     42                    contexts[node] = self.join(node, context)
     43                elif isinstance(node, planner.Sort):
     44                    contexts[node] = self.sort(node, context)
     45                elif isinstance(node, planner.SetOperation):
     46                    contexts[node] = self.set_operation(node, context)
     47                else:
     48                    raise NotImplementedError
     49
     50                finished.add(node)
     51
     52                for dep in node.dependents:
     53                    if all(d in contexts for d in dep.dependencies):
     54                        queue.add(dep)
     55
     56                for dep in node.dependencies:
     57                    if all(d in finished for d in dep.dependents):
     58                        contexts.pop(dep)
     59            except Exception as e:
     60                raise ExecuteError(f"Step '{node.id}' failed: {e}") from e
     61
     62        root = plan.root
     63        return contexts[root].tables[root.name]
     64
     65    def generate(self, expression):
     66        """Convert a SQL expression into literal Python code and compile it into bytecode."""
     67        if not expression:
     68            return None
     69
     70        sql = self.generator.generate(expression)
     71        return compile(sql, sql, "eval", optimize=2)
     72
     73    def generate_tuple(self, expressions):
     74        """Convert an array of SQL expressions into tuple of Python byte code."""
     75        if not expressions:
     76            return tuple()
     77        return tuple(self.generate(expression) for expression in expressions)
     78
     79    def context(self, tables):
     80        return Context(tables, env=self.env)
     81
     82    def table(self, expressions):
     83        return Table(
     84            expression.alias_or_name if isinstance(expression, exp.Expression) else expression
     85            for expression in expressions
     86        )
     87
     88    def scan(self, step, context):
     89        source = step.source
     90
     91        if source and isinstance(source, exp.Expression):
     92            source = source.name or source.alias
     93
     94        if source is None:
     95            context, table_iter = self.static()
     96        elif source in context:
     97            if not step.projections and not step.condition:
     98                return self.context({step.name: context.tables[source]})
     99            table_iter = context.table_iter(source)
    100        elif isinstance(step.source, exp.Table) and isinstance(step.source.this, exp.ReadCSV):
    101            table_iter = self.scan_csv(step)
    102            context = next(table_iter)
    103        else:
    104            context, table_iter = self.scan_table(step)
    105
    106        return self.context({step.name: self._project_and_filter(context, step, table_iter)})
    107
    108    def _project_and_filter(self, context, step, table_iter):
    109        sink = self.table(step.projections if step.projections else context.columns)
    110        condition = self.generate(step.condition)
    111        projections = self.generate_tuple(step.projections)
    112
    113        for reader in table_iter:
    114            if len(sink) >= step.limit:
    115                break
    116
    117            if condition and not context.eval(condition):
    118                continue
    119
    120            if projections:
    121                sink.append(context.eval_tuple(projections))
    122            else:
    123                sink.append(reader.row)
    124
    125        return sink
    126
    127    def static(self):
    128        return self.context({}), [RowReader(())]
    129
    130    def scan_table(self, step):
    131        table = self.tables.find(step.source)
    132        context = self.context({step.source.alias_or_name: table})
    133        return context, iter(table)
    134
    135    def scan_csv(self, step):
    136        alias = step.source.alias
    137        source = step.source.this
    138
    139        with csv_reader(source) as reader:
    140            columns = next(reader)
    141            table = Table(columns)
    142            context = self.context({alias: table})
    143            yield context
    144            types = []
    145
    146            for row in reader:
    147                if not types:
    148                    for v in row:
    149                        try:
    150                            types.append(type(ast.literal_eval(v)))
    151                        except (ValueError, SyntaxError):
    152                            types.append(str)
    153                context.set_row(tuple(t(v) for t, v in zip(types, row)))
    154                yield context.table.reader
    155
    156    def join(self, step, context):
    157        source = step.name
    158
    159        source_table = context.tables[source]
    160        source_context = self.context({source: source_table})
    161        column_ranges = {source: range(0, len(source_table.columns))}
    162
    163        for name, join in step.joins.items():
    164            table = context.tables[name]
    165            start = max(r.stop for r in column_ranges.values())
    166            column_ranges[name] = range(start, len(table.columns) + start)
    167            join_context = self.context({name: table})
    168
    169            if join.get("source_key"):
    170                table = self.hash_join(join, source_context, join_context)
    171            else:
    172                table = self.nested_loop_join(join, source_context, join_context)
    173
    174            source_context = self.context(
    175                {
    176                    name: Table(table.columns, table.rows, column_range)
    177                    for name, column_range in column_ranges.items()
    178                }
    179            )
    180            condition = self.generate(join["condition"])
    181            if condition:
    182                source_context.filter(condition)
    183
    184        if not step.condition and not step.projections:
    185            return source_context
    186
    187        sink = self._project_and_filter(
    188            source_context,
    189            step,
    190            (reader for reader, _ in iter(source_context)),
    191        )
    192
    193        if step.projections:
    194            return self.context({step.name: sink})
    195        else:
    196            return self.context(
    197                {
    198                    name: Table(table.columns, sink.rows, table.column_range)
    199                    for name, table in source_context.tables.items()
    200                }
    201            )
    202
    203    def nested_loop_join(self, _join, source_context, join_context):
    204        table = Table(source_context.columns + join_context.columns)
    205
    206        for reader_a, _ in source_context:
    207            for reader_b, _ in join_context:
    208                table.append(reader_a.row + reader_b.row)
    209
    210        return table
    211
    212    def hash_join(self, join, source_context, join_context):
    213        source_key = self.generate_tuple(join["source_key"])
    214        join_key = self.generate_tuple(join["join_key"])
    215        left = join.get("side") == "LEFT"
    216        right = join.get("side") == "RIGHT"
    217
    218        results = collections.defaultdict(lambda: ([], []))
    219
    220        for reader, ctx in source_context:
    221            results[ctx.eval_tuple(source_key)][0].append(reader.row)
    222        for reader, ctx in join_context:
    223            results[ctx.eval_tuple(join_key)][1].append(reader.row)
    224
    225        table = Table(source_context.columns + join_context.columns)
    226        nulls = [(None,) * len(join_context.columns if left else source_context.columns)]
    227
    228        for a_group, b_group in results.values():
    229            if left:
    230                b_group = b_group or nulls
    231            elif right:
    232                a_group = a_group or nulls
    233
    234            for a_row, b_row in itertools.product(a_group, b_group):
    235                table.append(a_row + b_row)
    236
    237        return table
    238
    239    def aggregate(self, step, context):
    240        group_by = self.generate_tuple(step.group.values())
    241        aggregations = self.generate_tuple(step.aggregations)
    242        operands = self.generate_tuple(step.operands)
    243
    244        if operands:
    245            operand_table = Table(self.table(step.operands).columns)
    246
    247            for reader, ctx in context:
    248                operand_table.append(ctx.eval_tuple(operands))
    249
    250            for i, (a, b) in enumerate(zip(context.table.rows, operand_table.rows)):
    251                context.table.rows[i] = a + b
    252
    253            width = len(context.columns)
    254            context.add_columns(*operand_table.columns)
    255
    256            operand_table = Table(
    257                context.columns,
    258                context.table.rows,
    259                range(width, width + len(operand_table.columns)),
    260            )
    261
    262            context = self.context(
    263                {
    264                    None: operand_table,
    265                    **context.tables,
    266                }
    267            )
    268
    269        context.sort(group_by)
    270
    271        group = None
    272        start = 0
    273        end = 1
    274        length = len(context.table)
    275        table = self.table(list(step.group) + step.aggregations)
    276
    277        def add_row():
    278            table.append(group + context.eval_tuple(aggregations))
    279
    280        if length:
    281            for i in range(length):
    282                context.set_index(i)
    283                key = context.eval_tuple(group_by)
    284                group = key if group is None else group
    285                end += 1
    286                if key != group:
    287                    context.set_range(start, end - 2)
    288                    add_row()
    289                    group = key
    290                    start = end - 2
    291                if len(table.rows) >= step.limit:
    292                    break
    293                if i == length - 1:
    294                    context.set_range(start, end - 1)
    295                    add_row()
    296        elif step.limit > 0 and not group_by:
    297            context.set_range(0, 0)
    298            table.append(context.eval_tuple(aggregations))
    299
    300        context = self.context({step.name: table, **{name: table for name in context.tables}})
    301
    302        if step.projections or step.condition:
    303            return self.scan(step, context)
    304        return context
    305
    306    def sort(self, step, context):
    307        projections = self.generate_tuple(step.projections)
    308        projection_columns = [p.alias_or_name for p in step.projections]
    309        all_columns = list(context.columns) + projection_columns
    310        sink = self.table(all_columns)
    311        for reader, ctx in context:
    312            sink.append(reader.row + ctx.eval_tuple(projections))
    313
    314        sort_ctx = self.context(
    315            {
    316                None: sink,
    317                **{table: sink for table in context.tables},
    318            }
    319        )
    320        sort_ctx.sort(self.generate_tuple(step.key))
    321
    322        if not math.isinf(step.limit):
    323            sort_ctx.table.rows = sort_ctx.table.rows[0 : step.limit]
    324
    325        output = Table(
    326            projection_columns,
    327            rows=[r[len(context.columns) : len(all_columns)] for r in sort_ctx.table.rows],
    328        )
    329        return self.context({step.name: output})
    330
    331    def set_operation(self, step, context):
    332        left = context.tables[step.left]
    333        right = context.tables[step.right]
    334
    335        sink = self.table(left.columns)
    336
    337        if issubclass(step.op, exp.Intersect):
    338            sink.rows = list(set(left.rows).intersection(set(right.rows)))
    339        elif issubclass(step.op, exp.Except):
    340            sink.rows = list(set(left.rows).difference(set(right.rows)))
    341        elif issubclass(step.op, exp.Union) and step.distinct:
    342            sink.rows = list(set(left.rows).union(set(right.rows)))
    343        else:
    344            sink.rows = left.rows + right.rows
    345
    346        return self.context({step.name: sink})
    347
    348
    349def _ordered_py(self, expression):
    350    this = self.sql(expression, "this")
    351    desc = "True" if expression.args.get("desc") else "False"
    352    nulls_first = "True" if expression.args.get("nulls_first") else "False"
    353    return f"ORDERED({this}, {desc}, {nulls_first})"
    354
    355
    356def _rename(self, e):
    357    try:
    358        values = list(e.args.values())
    359
    360        if len(values) == 1:
    361            values = values[0]
    362            if not isinstance(values, list):
    363                return self.func(e.key, values)
    364            return self.func(e.key, *values)
    365
    366        if isinstance(e, exp.Func) and e.is_var_len_args:
    367            *head, tail = values
    368            return self.func(e.key, *head, *tail)
    369
    370        return self.func(e.key, *values)
    371    except Exception as ex:
    372        raise Exception(f"Could not rename {repr(e)}") from ex
    373
    374
    375def _case_sql(self, expression):
    376    this = self.sql(expression, "this")
    377    chain = self.sql(expression, "default") or "None"
    378
    379    for e in reversed(expression.args["ifs"]):
    380        true = self.sql(e, "true")
    381        condition = self.sql(e, "this")
    382        condition = f"{this} = ({condition})" if this else condition
    383        chain = f"{true} if {condition} else ({chain})"
    384
    385    return chain
    386
    387
    388def _lambda_sql(self, e: exp.Lambda) -> str:
    389    names = {e.name.lower() for e in e.expressions}
    390
    391    e = e.transform(
    392        lambda n: exp.var(n.name)
    393        if isinstance(n, exp.Identifier) and n.name.lower() in names
    394        else n
    395    )
    396
    397    return f"lambda {self.expressions(e, flat=True)}: {self.sql(e, 'this')}"
    398
    399
    400class Python(Dialect):
    401    class Tokenizer(tokens.Tokenizer):
    402        STRING_ESCAPES = ["\\"]
    403
    404    class Generator(generator.Generator):
    405        TRANSFORMS = {
    406            **{klass: _rename for klass in subclasses(exp.__name__, exp.Binary)},
    407            **{klass: _rename for klass in exp.ALL_FUNCTIONS},
    408            exp.Case: _case_sql,
    409            exp.Alias: lambda self, e: self.sql(e.this),
    410            exp.Array: inline_array_sql,
    411            exp.And: lambda self, e: self.binary(e, "and"),
    412            exp.Between: _rename,
    413            exp.Boolean: lambda self, e: "True" if e.this else "False",
    414            exp.Cast: lambda self, e: f"CAST({self.sql(e.this)}, exp.DataType.Type.{e.args['to']})",
    415            exp.Column: lambda self, e: f"scope[{self.sql(e, 'table') or None}][{self.sql(e.this)}]",
    416            exp.Distinct: lambda self, e: f"set({self.sql(e, 'this')})",
    417            exp.Extract: lambda self, e: f"EXTRACT('{e.name.lower()}', {self.sql(e, 'expression')})",
    418            exp.In: lambda self, e: f"{self.sql(e, 'this')} in {{{self.expressions(e, flat=True)}}}",
    419            exp.Interval: lambda self, e: f"INTERVAL({self.sql(e.this)}, '{self.sql(e.unit)}')",
    420            exp.Is: lambda self, e: self.binary(e, "==")
    421            if isinstance(e.this, exp.Literal)
    422            else self.binary(e, "is"),
    423            exp.Lambda: _lambda_sql,
    424            exp.Not: lambda self, e: f"not {self.sql(e.this)}",
    425            exp.Null: lambda *_: "None",
    426            exp.Or: lambda self, e: self.binary(e, "or"),
    427            exp.Ordered: _ordered_py,
    428            exp.Star: lambda *_: "1",
    429        }

class PythonExecutor: View Source

     16class PythonExecutor:
     17    def __init__(self, env=None, tables=None):
     18        self.generator = Python().generator(identify=True, comments=False)
     19        self.env = {**ENV, **(env or {})}
     20        self.tables = tables or {}
     21
     22    def execute(self, plan):
     23        finished = set()
     24        queue = set(plan.leaves)
     25        contexts = {}
     26
     27        while queue:
     28            node = queue.pop()
     29            try:
     30                context = self.context(
     31                    {
     32                        name: table
     33                        for dep in node.dependencies
     34                        for name, table in contexts[dep].tables.items()
     35                    }
     36                )
     37
     38                if isinstance(node, planner.Scan):
     39                    contexts[node] = self.scan(node, context)
     40                elif isinstance(node, planner.Aggregate):
     41                    contexts[node] = self.aggregate(node, context)
     42                elif isinstance(node, planner.Join):
     43                    contexts[node] = self.join(node, context)
     44                elif isinstance(node, planner.Sort):
     45                    contexts[node] = self.sort(node, context)
     46                elif isinstance(node, planner.SetOperation):
     47                    contexts[node] = self.set_operation(node, context)
     48                else:
     49                    raise NotImplementedError
     50
     51                finished.add(node)
     52
     53                for dep in node.dependents:
     54                    if all(d in contexts for d in dep.dependencies):
     55                        queue.add(dep)
     56
     57                for dep in node.dependencies:
     58                    if all(d in finished for d in dep.dependents):
     59                        contexts.pop(dep)
     60            except Exception as e:
     61                raise ExecuteError(f"Step '{node.id}' failed: {e}") from e
     62
     63        root = plan.root
     64        return contexts[root].tables[root.name]
     65
     66    def generate(self, expression):
     67        """Convert a SQL expression into literal Python code and compile it into bytecode."""
     68        if not expression:
     69            return None
     70
     71        sql = self.generator.generate(expression)
     72        return compile(sql, sql, "eval", optimize=2)
     73
     74    def generate_tuple(self, expressions):
     75        """Convert an array of SQL expressions into tuple of Python byte code."""
     76        if not expressions:
     77            return tuple()
     78        return tuple(self.generate(expression) for expression in expressions)
     79
     80    def context(self, tables):
     81        return Context(tables, env=self.env)
     82
     83    def table(self, expressions):
     84        return Table(
     85            expression.alias_or_name if isinstance(expression, exp.Expression) else expression
     86            for expression in expressions
     87        )
     88
     89    def scan(self, step, context):
     90        source = step.source
     91
     92        if source and isinstance(source, exp.Expression):
     93            source = source.name or source.alias
     94
     95        if source is None:
     96            context, table_iter = self.static()
     97        elif source in context:
     98            if not step.projections and not step.condition:
     99                return self.context({step.name: context.tables[source]})
    100            table_iter = context.table_iter(source)
    101        elif isinstance(step.source, exp.Table) and isinstance(step.source.this, exp.ReadCSV):
    102            table_iter = self.scan_csv(step)
    103            context = next(table_iter)
    104        else:
    105            context, table_iter = self.scan_table(step)
    106
    107        return self.context({step.name: self._project_and_filter(context, step, table_iter)})
    108
    109    def _project_and_filter(self, context, step, table_iter):
    110        sink = self.table(step.projections if step.projections else context.columns)
    111        condition = self.generate(step.condition)
    112        projections = self.generate_tuple(step.projections)
    113
    114        for reader in table_iter:
    115            if len(sink) >= step.limit:
    116                break
    117
    118            if condition and not context.eval(condition):
    119                continue
    120
    121            if projections:
    122                sink.append(context.eval_tuple(projections))
    123            else:
    124                sink.append(reader.row)
    125
    126        return sink
    127
    128    def static(self):
    129        return self.context({}), [RowReader(())]
    130
    131    def scan_table(self, step):
    132        table = self.tables.find(step.source)
    133        context = self.context({step.source.alias_or_name: table})
    134        return context, iter(table)
    135
    136    def scan_csv(self, step):
    137        alias = step.source.alias
    138        source = step.source.this
    139
    140        with csv_reader(source) as reader:
    141            columns = next(reader)
    142            table = Table(columns)
    143            context = self.context({alias: table})
    144            yield context
    145            types = []
    146
    147            for row in reader:
    148                if not types:
    149                    for v in row:
    150                        try:
    151                            types.append(type(ast.literal_eval(v)))
    152                        except (ValueError, SyntaxError):
    153                            types.append(str)
    154                context.set_row(tuple(t(v) for t, v in zip(types, row)))
    155                yield context.table.reader
    156
    157    def join(self, step, context):
    158        source = step.name
    159
    160        source_table = context.tables[source]
    161        source_context = self.context({source: source_table})
    162        column_ranges = {source: range(0, len(source_table.columns))}
    163
    164        for name, join in step.joins.items():
    165            table = context.tables[name]
    166            start = max(r.stop for r in column_ranges.values())
    167            column_ranges[name] = range(start, len(table.columns) + start)
    168            join_context = self.context({name: table})
    169
    170            if join.get("source_key"):
    171                table = self.hash_join(join, source_context, join_context)
    172            else:
    173                table = self.nested_loop_join(join, source_context, join_context)
    174
    175            source_context = self.context(
    176                {
    177                    name: Table(table.columns, table.rows, column_range)
    178                    for name, column_range in column_ranges.items()
    179                }
    180            )
    181            condition = self.generate(join["condition"])
    182            if condition:
    183                source_context.filter(condition)
    184
    185        if not step.condition and not step.projections:
    186            return source_context
    187
    188        sink = self._project_and_filter(
    189            source_context,
    190            step,
    191            (reader for reader, _ in iter(source_context)),
    192        )
    193
    194        if step.projections:
    195            return self.context({step.name: sink})
    196        else:
    197            return self.context(
    198                {
    199                    name: Table(table.columns, sink.rows, table.column_range)
    200                    for name, table in source_context.tables.items()
    201                }
    202            )
    203
    204    def nested_loop_join(self, _join, source_context, join_context):
    205        table = Table(source_context.columns + join_context.columns)
    206
    207        for reader_a, _ in source_context:
    208            for reader_b, _ in join_context:
    209                table.append(reader_a.row + reader_b.row)
    210
    211        return table
    212
    213    def hash_join(self, join, source_context, join_context):
    214        source_key = self.generate_tuple(join["source_key"])
    215        join_key = self.generate_tuple(join["join_key"])
    216        left = join.get("side") == "LEFT"
    217        right = join.get("side") == "RIGHT"
    218
    219        results = collections.defaultdict(lambda: ([], []))
    220
    221        for reader, ctx in source_context:
    222            results[ctx.eval_tuple(source_key)][0].append(reader.row)
    223        for reader, ctx in join_context:
    224            results[ctx.eval_tuple(join_key)][1].append(reader.row)
    225
    226        table = Table(source_context.columns + join_context.columns)
    227        nulls = [(None,) * len(join_context.columns if left else source_context.columns)]
    228
    229        for a_group, b_group in results.values():
    230            if left:
    231                b_group = b_group or nulls
    232            elif right:
    233                a_group = a_group or nulls
    234
    235            for a_row, b_row in itertools.product(a_group, b_group):
    236                table.append(a_row + b_row)
    237
    238        return table
    239
    240    def aggregate(self, step, context):
    241        group_by = self.generate_tuple(step.group.values())
    242        aggregations = self.generate_tuple(step.aggregations)
    243        operands = self.generate_tuple(step.operands)
    244
    245        if operands:
    246            operand_table = Table(self.table(step.operands).columns)
    247
    248            for reader, ctx in context:
    249                operand_table.append(ctx.eval_tuple(operands))
    250
    251            for i, (a, b) in enumerate(zip(context.table.rows, operand_table.rows)):
    252                context.table.rows[i] = a + b
    253
    254            width = len(context.columns)
    255            context.add_columns(*operand_table.columns)
    256
    257            operand_table = Table(
    258                context.columns,
    259                context.table.rows,
    260                range(width, width + len(operand_table.columns)),
    261            )
    262
    263            context = self.context(
    264                {
    265                    None: operand_table,
    266                    **context.tables,
    267                }
    268            )
    269
    270        context.sort(group_by)
    271
    272        group = None
    273        start = 0
    274        end = 1
    275        length = len(context.table)
    276        table = self.table(list(step.group) + step.aggregations)
    277
    278        def add_row():
    279            table.append(group + context.eval_tuple(aggregations))
    280
    281        if length:
    282            for i in range(length):
    283                context.set_index(i)
    284                key = context.eval_tuple(group_by)
    285                group = key if group is None else group
    286                end += 1
    287                if key != group:
    288                    context.set_range(start, end - 2)
    289                    add_row()
    290                    group = key
    291                    start = end - 2
    292                if len(table.rows) >= step.limit:
    293                    break
    294                if i == length - 1:
    295                    context.set_range(start, end - 1)
    296                    add_row()
    297        elif step.limit > 0 and not group_by:
    298            context.set_range(0, 0)
    299            table.append(context.eval_tuple(aggregations))
    300
    301        context = self.context({step.name: table, **{name: table for name in context.tables}})
    302
    303        if step.projections or step.condition:
    304            return self.scan(step, context)
    305        return context
    306
    307    def sort(self, step, context):
    308        projections = self.generate_tuple(step.projections)
    309        projection_columns = [p.alias_or_name for p in step.projections]
    310        all_columns = list(context.columns) + projection_columns
    311        sink = self.table(all_columns)
    312        for reader, ctx in context:
    313            sink.append(reader.row + ctx.eval_tuple(projections))
    314
    315        sort_ctx = self.context(
    316            {
    317                None: sink,
    318                **{table: sink for table in context.tables},
    319            }
    320        )
    321        sort_ctx.sort(self.generate_tuple(step.key))
    322
    323        if not math.isinf(step.limit):
    324            sort_ctx.table.rows = sort_ctx.table.rows[0 : step.limit]
    325
    326        output = Table(
    327            projection_columns,
    328            rows=[r[len(context.columns) : len(all_columns)] for r in sort_ctx.table.rows],
    329        )
    330        return self.context({step.name: output})
    331
    332    def set_operation(self, step, context):
    333        left = context.tables[step.left]
    334        right = context.tables[step.right]
    335
    336        sink = self.table(left.columns)
    337
    338        if issubclass(step.op, exp.Intersect):
    339            sink.rows = list(set(left.rows).intersection(set(right.rows)))
    340        elif issubclass(step.op, exp.Except):
    341            sink.rows = list(set(left.rows).difference(set(right.rows)))
    342        elif issubclass(step.op, exp.Union) and step.distinct:
    343            sink.rows = list(set(left.rows).union(set(right.rows)))
    344        else:
    345            sink.rows = left.rows + right.rows
    346
    347        return self.context({step.name: sink})

PythonExecutor(env=None, tables=None) View Source

    17    def __init__(self, env=None, tables=None):
    18        self.generator = Python().generator(identify=True, comments=False)
    19        self.env = {**ENV, **(env or {})}
    20        self.tables = tables or {}

generator
env
tables
def execute(self, plan): View Source

    22    def execute(self, plan):
    23        finished = set()
    24        queue = set(plan.leaves)
    25        contexts = {}
    26
    27        while queue:
    28            node = queue.pop()
    29            try:
    30                context = self.context(
    31                    {
    32                        name: table
    33                        for dep in node.dependencies
    34                        for name, table in contexts[dep].tables.items()
    35                    }
    36                )
    37
    38                if isinstance(node, planner.Scan):
    39                    contexts[node] = self.scan(node, context)
    40                elif isinstance(node, planner.Aggregate):
    41                    contexts[node] = self.aggregate(node, context)
    42                elif isinstance(node, planner.Join):
    43                    contexts[node] = self.join(node, context)
    44                elif isinstance(node, planner.Sort):
    45                    contexts[node] = self.sort(node, context)
    46                elif isinstance(node, planner.SetOperation):
    47                    contexts[node] = self.set_operation(node, context)
    48                else:
    49                    raise NotImplementedError
    50
    51                finished.add(node)
    52
    53                for dep in node.dependents:
    54                    if all(d in contexts for d in dep.dependencies):
    55                        queue.add(dep)
    56
    57                for dep in node.dependencies:
    58                    if all(d in finished for d in dep.dependents):
    59                        contexts.pop(dep)
    60            except Exception as e:
    61                raise ExecuteError(f"Step '{node.id}' failed: {e}") from e
    62
    63        root = plan.root
    64        return contexts[root].tables[root.name]

def generate(self, expression): View Source

    66    def generate(self, expression):
    67        """Convert a SQL expression into literal Python code and compile it into bytecode."""
    68        if not expression:
    69            return None
    70
    71        sql = self.generator.generate(expression)
    72        return compile(sql, sql, "eval", optimize=2)

Convert a SQL expression into literal Python code and compile it into bytecode.

def generate_tuple(self, expressions): View Source

    74    def generate_tuple(self, expressions):
    75        """Convert an array of SQL expressions into tuple of Python byte code."""
    76        if not expressions:
    77            return tuple()
    78        return tuple(self.generate(expression) for expression in expressions)

Convert an array of SQL expressions into tuple of Python byte code.

def context(self, tables): View Source

    80    def context(self, tables):
    81        return Context(tables, env=self.env)

def table(self, expressions): View Source

    83    def table(self, expressions):
    84        return Table(
    85            expression.alias_or_name if isinstance(expression, exp.Expression) else expression
    86            for expression in expressions
    87        )

def scan(self, step, context): View Source

     89    def scan(self, step, context):
     90        source = step.source
     91
     92        if source and isinstance(source, exp.Expression):
     93            source = source.name or source.alias
     94
     95        if source is None:
     96            context, table_iter = self.static()
     97        elif source in context:
     98            if not step.projections and not step.condition:
     99                return self.context({step.name: context.tables[source]})
    100            table_iter = context.table_iter(source)
    101        elif isinstance(step.source, exp.Table) and isinstance(step.source.this, exp.ReadCSV):
    102            table_iter = self.scan_csv(step)
    103            context = next(table_iter)
    104        else:
    105            context, table_iter = self.scan_table(step)
    106
    107        return self.context({step.name: self._project_and_filter(context, step, table_iter)})

def static(self): View Source

    128    def static(self):
    129        return self.context({}), [RowReader(())]

def scan_table(self, step): View Source

    131    def scan_table(self, step):
    132        table = self.tables.find(step.source)
    133        context = self.context({step.source.alias_or_name: table})
    134        return context, iter(table)

def scan_csv(self, step): View Source

    136    def scan_csv(self, step):
    137        alias = step.source.alias
    138        source = step.source.this
    139
    140        with csv_reader(source) as reader:
    141            columns = next(reader)
    142            table = Table(columns)
    143            context = self.context({alias: table})
    144            yield context
    145            types = []
    146
    147            for row in reader:
    148                if not types:
    149                    for v in row:
    150                        try:
    151                            types.append(type(ast.literal_eval(v)))
    152                        except (ValueError, SyntaxError):
    153                            types.append(str)
    154                context.set_row(tuple(t(v) for t, v in zip(types, row)))
    155                yield context.table.reader

def join(self, step, context): View Source

    157    def join(self, step, context):
    158        source = step.name
    159
    160        source_table = context.tables[source]
    161        source_context = self.context({source: source_table})
    162        column_ranges = {source: range(0, len(source_table.columns))}
    163
    164        for name, join in step.joins.items():
    165            table = context.tables[name]
    166            start = max(r.stop for r in column_ranges.values())
    167            column_ranges[name] = range(start, len(table.columns) + start)
    168            join_context = self.context({name: table})
    169
    170            if join.get("source_key"):
    171                table = self.hash_join(join, source_context, join_context)
    172            else:
    173                table = self.nested_loop_join(join, source_context, join_context)
    174
    175            source_context = self.context(
    176                {
    177                    name: Table(table.columns, table.rows, column_range)
    178                    for name, column_range in column_ranges.items()
    179                }
    180            )
    181            condition = self.generate(join["condition"])
    182            if condition:
    183                source_context.filter(condition)
    184
    185        if not step.condition and not step.projections:
    186            return source_context
    187
    188        sink = self._project_and_filter(
    189            source_context,
    190            step,
    191            (reader for reader, _ in iter(source_context)),
    192        )
    193
    194        if step.projections:
    195            return self.context({step.name: sink})
    196        else:
    197            return self.context(
    198                {
    199                    name: Table(table.columns, sink.rows, table.column_range)
    200                    for name, table in source_context.tables.items()
    201                }
    202            )

def nested_loop_join(self, _join, source_context, join_context): View Source

    204    def nested_loop_join(self, _join, source_context, join_context):
    205        table = Table(source_context.columns + join_context.columns)
    206
    207        for reader_a, _ in source_context:
    208            for reader_b, _ in join_context:
    209                table.append(reader_a.row + reader_b.row)
    210
    211        return table

def hash_join(self, join, source_context, join_context): View Source

    213    def hash_join(self, join, source_context, join_context):
    214        source_key = self.generate_tuple(join["source_key"])
    215        join_key = self.generate_tuple(join["join_key"])
    216        left = join.get("side") == "LEFT"
    217        right = join.get("side") == "RIGHT"
    218
    219        results = collections.defaultdict(lambda: ([], []))
    220
    221        for reader, ctx in source_context:
    222            results[ctx.eval_tuple(source_key)][0].append(reader.row)
    223        for reader, ctx in join_context:
    224            results[ctx.eval_tuple(join_key)][1].append(reader.row)
    225
    226        table = Table(source_context.columns + join_context.columns)
    227        nulls = [(None,) * len(join_context.columns if left else source_context.columns)]
    228
    229        for a_group, b_group in results.values():
    230            if left:
    231                b_group = b_group or nulls
    232            elif right:
    233                a_group = a_group or nulls
    234
    235            for a_row, b_row in itertools.product(a_group, b_group):
    236                table.append(a_row + b_row)
    237
    238        return table

def aggregate(self, step, context): View Source

    240    def aggregate(self, step, context):
    241        group_by = self.generate_tuple(step.group.values())
    242        aggregations = self.generate_tuple(step.aggregations)
    243        operands = self.generate_tuple(step.operands)
    244
    245        if operands:
    246            operand_table = Table(self.table(step.operands).columns)
    247
    248            for reader, ctx in context:
    249                operand_table.append(ctx.eval_tuple(operands))
    250
    251            for i, (a, b) in enumerate(zip(context.table.rows, operand_table.rows)):
    252                context.table.rows[i] = a + b
    253
    254            width = len(context.columns)
    255            context.add_columns(*operand_table.columns)
    256
    257            operand_table = Table(
    258                context.columns,
    259                context.table.rows,
    260                range(width, width + len(operand_table.columns)),
    261            )
    262
    263            context = self.context(
    264                {
    265                    None: operand_table,
    266                    **context.tables,
    267                }
    268            )
    269
    270        context.sort(group_by)
    271
    272        group = None
    273        start = 0
    274        end = 1
    275        length = len(context.table)
    276        table = self.table(list(step.group) + step.aggregations)
    277
    278        def add_row():
    279            table.append(group + context.eval_tuple(aggregations))
    280
    281        if length:
    282            for i in range(length):
    283                context.set_index(i)
    284                key = context.eval_tuple(group_by)
    285                group = key if group is None else group
    286                end += 1
    287                if key != group:
    288                    context.set_range(start, end - 2)
    289                    add_row()
    290                    group = key
    291                    start = end - 2
    292                if len(table.rows) >= step.limit:
    293                    break
    294                if i == length - 1:
    295                    context.set_range(start, end - 1)
    296                    add_row()
    297        elif step.limit > 0 and not group_by:
    298            context.set_range(0, 0)
    299            table.append(context.eval_tuple(aggregations))
    300
    301        context = self.context({step.name: table, **{name: table for name in context.tables}})
    302
    303        if step.projections or step.condition:
    304            return self.scan(step, context)
    305        return context

def sort(self, step, context): View Source

    307    def sort(self, step, context):
    308        projections = self.generate_tuple(step.projections)
    309        projection_columns = [p.alias_or_name for p in step.projections]
    310        all_columns = list(context.columns) + projection_columns
    311        sink = self.table(all_columns)
    312        for reader, ctx in context:
    313            sink.append(reader.row + ctx.eval_tuple(projections))
    314
    315        sort_ctx = self.context(
    316            {
    317                None: sink,
    318                **{table: sink for table in context.tables},
    319            }
    320        )
    321        sort_ctx.sort(self.generate_tuple(step.key))
    322
    323        if not math.isinf(step.limit):
    324            sort_ctx.table.rows = sort_ctx.table.rows[0 : step.limit]
    325
    326        output = Table(
    327            projection_columns,
    328            rows=[r[len(context.columns) : len(all_columns)] for r in sort_ctx.table.rows],
    329        )
    330        return self.context({step.name: output})

def set_operation(self, step, context): View Source

    332    def set_operation(self, step, context):
    333        left = context.tables[step.left]
    334        right = context.tables[step.right]
    335
    336        sink = self.table(left.columns)
    337
    338        if issubclass(step.op, exp.Intersect):
    339            sink.rows = list(set(left.rows).intersection(set(right.rows)))
    340        elif issubclass(step.op, exp.Except):
    341            sink.rows = list(set(left.rows).difference(set(right.rows)))
    342        elif issubclass(step.op, exp.Union) and step.distinct:
    343            sink.rows = list(set(left.rows).union(set(right.rows)))
    344        else:
    345            sink.rows = left.rows + right.rows
    346
    347        return self.context({step.name: sink})

class Python(sqlglot.dialects.dialect.Dialect): View Source

    401class Python(Dialect):
    402    class Tokenizer(tokens.Tokenizer):
    403        STRING_ESCAPES = ["\\"]
    404
    405    class Generator(generator.Generator):
    406        TRANSFORMS = {
    407            **{klass: _rename for klass in subclasses(exp.__name__, exp.Binary)},
    408            **{klass: _rename for klass in exp.ALL_FUNCTIONS},
    409            exp.Case: _case_sql,
    410            exp.Alias: lambda self, e: self.sql(e.this),
    411            exp.Array: inline_array_sql,
    412            exp.And: lambda self, e: self.binary(e, "and"),
    413            exp.Between: _rename,
    414            exp.Boolean: lambda self, e: "True" if e.this else "False",
    415            exp.Cast: lambda self, e: f"CAST({self.sql(e.this)}, exp.DataType.Type.{e.args['to']})",
    416            exp.Column: lambda self, e: f"scope[{self.sql(e, 'table') or None}][{self.sql(e.this)}]",
    417            exp.Distinct: lambda self, e: f"set({self.sql(e, 'this')})",
    418            exp.Extract: lambda self, e: f"EXTRACT('{e.name.lower()}', {self.sql(e, 'expression')})",
    419            exp.In: lambda self, e: f"{self.sql(e, 'this')} in {{{self.expressions(e, flat=True)}}}",
    420            exp.Interval: lambda self, e: f"INTERVAL({self.sql(e.this)}, '{self.sql(e.unit)}')",
    421            exp.Is: lambda self, e: self.binary(e, "==")
    422            if isinstance(e.this, exp.Literal)
    423            else self.binary(e, "is"),
    424            exp.Lambda: _lambda_sql,
    425            exp.Not: lambda self, e: f"not {self.sql(e.this)}",
    426            exp.Null: lambda *_: "None",
    427            exp.Or: lambda self, e: self.binary(e, "or"),
    428            exp.Ordered: _ordered_py,
    429            exp.Star: lambda *_: "1",
    430        }

tokenizer_class = <class 'Python.Tokenizer'>
parser_class = <class 'sqlglot.parser.Parser'>
generator_class = <class 'Python.Generator'>
TIME_TRIE: Dict = {}
FORMAT_TRIE: Dict = {}
INVERSE_TIME_MAPPING: Dict[str, str] = {}
INVERSE_TIME_TRIE: Dict = {}
INVERSE_ESCAPE_SEQUENCES: Dict[str, str] = {}
QUOTE_START = "'"
QUOTE_END = "'"
IDENTIFIER_START = '"'
IDENTIFIER_END = '"'
BIT_START = None
BIT_END = None
HEX_START = None
HEX_END = None
BYTE_START = None
BYTE_END = None

##### Inherited Members

sqlglot.dialects.dialect.Dialect
  INDEX_OFFSET
  UNNEST_COLUMN_ONLY
  ALIAS_POST_TABLESAMPLE
  RESOLVES_IDENTIFIERS_AS_UPPERCASE
  IDENTIFIERS_CAN_START_WITH_DIGIT
  DPIPE_IS_STRING_CONCAT
  STRICT_STRING_CONCAT
  SUPPORTS_USER_DEFINED_TYPES
  SUPPORTS_SEMI_ANTI_JOIN
  NORMALIZE_FUNCTIONS
  LOG_BASE_FIRST
  NULL_ORDERING
  DATE_FORMAT
  DATEINT_FORMAT
  TIME_FORMAT
  TIME_MAPPING
  FORMAT_MAPPING
  ESCAPE_SEQUENCES
  PSEUDOCOLUMNS
  get_or_raise
  format_time
  normalize_identifier
  case_sensitive
  can_identify
  quote_identifier
  parse
  parse_into
  generate
  transpile
  tokenize
  tokenizer
  parser
  generator

class Python.Tokenizer(sqlglot.tokens.Tokenizer): View Source

    402    class Tokenizer(tokens.Tokenizer):
    403        STRING_ESCAPES = ["\\"]

STRING_ESCAPES = ['\\']

##### Inherited Members

sqlglot.tokens.Tokenizer
  SINGLE_TOKENS
  BIT_STRINGS
  BYTE_STRINGS
  HEX_STRINGS
  RAW_STRINGS
  HEREDOC_STRINGS
  IDENTIFIERS
  IDENTIFIER_ESCAPES
  QUOTES
  VAR_SINGLE_TOKENS
  ESCAPE_SEQUENCES
  IDENTIFIERS_CAN_START_WITH_DIGIT
  KEYWORDS
  WHITE_SPACE
  COMMANDS
  COMMAND_PREFIX_TOKENS
  NUMERIC_LITERALS
  ENCODE
  COMMENTS
  reset
  tokenize
  peek
  size
  sql
  tokens

class Python.Generator(sqlglot.generator.Generator): View Source

    405    class Generator(generator.Generator):
    406        TRANSFORMS = {
    407            **{klass: _rename for klass in subclasses(exp.__name__, exp.Binary)},
    408            **{klass: _rename for klass in exp.ALL_FUNCTIONS},
    409            exp.Case: _case_sql,
    410            exp.Alias: lambda self, e: self.sql(e.this),
    411            exp.Array: inline_array_sql,
    412            exp.And: lambda self, e: self.binary(e, "and"),
    413            exp.Between: _rename,
    414            exp.Boolean: lambda self, e: "True" if e.this else "False",
    415            exp.Cast: lambda self, e: f"CAST({self.sql(e.this)}, exp.DataType.Type.{e.args['to']})",
    416            exp.Column: lambda self, e: f"scope[{self.sql(e, 'table') or None}][{self.sql(e.this)}]",
    417            exp.Distinct: lambda self, e: f"set({self.sql(e, 'this')})",
    418            exp.Extract: lambda self, e: f"EXTRACT('{e.name.lower()}', {self.sql(e, 'expression')})",
    419            exp.In: lambda self, e: f"{self.sql(e, 'this')} in {{{self.expressions(e, flat=True)}}}",
    420            exp.Interval: lambda self, e: f"INTERVAL({self.sql(e.this)}, '{self.sql(e.unit)}')",
    421            exp.Is: lambda self, e: self.binary(e, "==")
    422            if isinstance(e.this, exp.Literal)
    423            else self.binary(e, "is"),
    424            exp.Lambda: _lambda_sql,
    425            exp.Not: lambda self, e: f"not {self.sql(e.this)}",
    426            exp.Null: lambda *_: "None",
    427            exp.Or: lambda self, e: self.binary(e, "or"),
    428            exp.Ordered: _ordered_py,
    429            exp.Star: lambda *_: "1",
    430        }

Generator converts a given syntax tree to the corresponding SQL string.

###### Arguments:

- pretty: Whether or not to format the produced SQL string. Default: False.
- identify: Determines when an identifier should be quoted. Possible values are: False (default): Never quote, except in cases where it's mandatory by the dialect. True or 'always': Always quote. 'safe': Only quote identifiers that are case insensitive.
- normalize: Whether or not to normalize identifiers to lowercase. Default: False.
- pad: Determines the pad size in a formatted string. Default: 2.
- indent: Determines the indentation size in a formatted string. Default: 2.
- normalize_functions: Whether or not to normalize all function names. Possible values are: "upper" or True (default): Convert names to uppercase. "lower": Convert names to lowercase. False: Disables function name normalization.
- unsupported_level: Determines the generator's behavior when it encounters unsupported expressions. Default ErrorLevel.WARN.
- max_unsupported: Maximum number of unsupported messages to include in a raised UnsupportedError. This is only relevant if unsupported_level is ErrorLevel.RAISE. Default: 3
- leading_comma: Determines whether or not the comma is leading or trailing in select expressions. This is only relevant when generating in pretty mode. Default: False
- max_text_width: The max number of characters in a segment before creating new lines in pretty mode. The default is on the smaller end because the length only represents a segment and not the true line length. Default: 80
- comments: Whether or not to preserve comments in the output SQL code. Default: True

TRANSFORMS = {<class 'sqlglot.expressions.Add'>: <function _rename>, <class 'sqlglot.expressions.And'>: <function Python.Generator.<lambda>>, <class 'sqlglot.expressions.ArrayContained'>: <function _rename>, <class 'sqlglot.expressions.ArrayContains'>: <function _rename>, <class 'sqlglot.expressions.ArrayOverlaps'>: <function _rename>, <class 'sqlglot.expressions.Binary'>: <function _rename>, <class 'sqlglot.expressions.BitwiseAnd'>: <function _rename>, <class 'sqlglot.expressions.BitwiseLeftShift'>: <function _rename>, <class 'sqlglot.expressions.BitwiseOr'>: <function _rename>, <class 'sqlglot.expressions.BitwiseRightShift'>: <function _rename>, <class 'sqlglot.expressions.BitwiseXor'>: <function _rename>, <class 'sqlglot.expressions.Collate'>: <function _rename>, <class 'sqlglot.expressions.Connector'>: <function _rename>, <class 'sqlglot.expressions.DPipe'>: <function _rename>, <class 'sqlglot.expressions.Distance'>: <function _rename>, <class 'sqlglot.expressions.Div'>: <function _rename>, <class 'sqlglot.expressions.Dot'>: <function _rename>, <class 'sqlglot.expressions.EQ'>: <function _rename>, <class 'sqlglot.expressions.Escape'>: <function _rename>, <class 'sqlglot.expressions.GT'>: <function _rename>, <class 'sqlglot.expressions.GTE'>: <function _rename>, <class 'sqlglot.expressions.Glob'>: <function _rename>, <class 'sqlglot.expressions.ILike'>: <function _rename>, <class 'sqlglot.expressions.ILikeAny'>: <function _rename>, <class 'sqlglot.expressions.IntDiv'>: <function _rename>, <class 'sqlglot.expressions.Is'>: <function Python.Generator.<lambda>>, <class 'sqlglot.expressions.JSONArrayContains'>: <function _rename>, <class 'sqlglot.expressions.JSONBContains'>: <function _rename>, <class 'sqlglot.expressions.JSONBExtract'>: <function _rename>, <class 'sqlglot.expressions.JSONBExtractScalar'>: <function _rename>, <class 'sqlglot.expressions.JSONExtract'>: <function _rename>, <class 'sqlglot.expressions.JSONExtractScalar'>: <function _rename>, <class 'sqlglot.expressions.Kwarg'>: <function _rename>, <class 'sqlglot.expressions.LT'>: <function _rename>, <class 'sqlglot.expressions.LTE'>: <function _rename>, <class 'sqlglot.expressions.Like'>: <function _rename>, <class 'sqlglot.expressions.LikeAny'>: <function _rename>, <class 'sqlglot.expressions.Mod'>: <function _rename>, <class 'sqlglot.expressions.Mul'>: <function _rename>, <class 'sqlglot.expressions.NEQ'>: <function _rename>, <class 'sqlglot.expressions.NullSafeEQ'>: <function _rename>, <class 'sqlglot.expressions.NullSafeNEQ'>: <function _rename>, <class 'sqlglot.expressions.Or'>: <function Python.Generator.<lambda>>, <class 'sqlglot.expressions.Overlaps'>: <function _rename>, <class 'sqlglot.expressions.Pow'>: <function _rename>, <class 'sqlglot.expressions.RegexpLike'>: <function _rename>, <class 'sqlglot.expressions.SafeDPipe'>: <function _rename>, <class 'sqlglot.expressions.SimilarTo'>: <function _rename>, <class 'sqlglot.expressions.Slice'>: <function _rename>, <class 'sqlglot.expressions.Sub'>: <function _rename>, <class 'sqlglot.expressions.Xor'>: <function _rename>, <class 'sqlglot.expressions.Abs'>: <function _rename>, <class 'sqlglot.expressions.AnyValue'>: <function _rename>, <class 'sqlglot.expressions.ApproxDistinct'>: <function _rename>, <class 'sqlglot.expressions.ApproxQuantile'>: <function _rename>, <class 'sqlglot.expressions.Array'>: <function inline_array_sql>, <class 'sqlglot.expressions.ArrayAgg'>: <function _rename>, <class 'sqlglot.expressions.ArrayAll'>: <function _rename>, <class 'sqlglot.expressions.ArrayAny'>: <function _rename>, <class 'sqlglot.expressions.ArrayConcat'>: <function _rename>, <class 'sqlglot.expressions.ArrayFilter'>: <function _rename>, <class 'sqlglot.expressions.ArrayJoin'>: <function _rename>, <class 'sqlglot.expressions.ArraySize'>: <function _rename>, <class 'sqlglot.expressions.ArraySort'>: <function _rename>, <class 'sqlglot.expressions.ArraySum'>: <function _rename>, <class 'sqlglot.expressions.ArrayUnionAgg'>: <function _rename>, <class 'sqlglot.expressions.Avg'>: <function _rename>, <class 'sqlglot.expressions.Case'>: <function _case_sql>, <class 'sqlglot.expressions.Cast'>: <function Python.Generator.<lambda>>, <class 'sqlglot.expressions.CastToStrType'>: <function _rename>, <class 'sqlglot.expressions.Ceil'>: <function _rename>, <class 'sqlglot.expressions.Chr'>: <function _rename>, <class 'sqlglot.expressions.Coalesce'>: <function _rename>, <class 'sqlglot.expressions.Concat'>: <function _rename>, <class 'sqlglot.expressions.ConcatWs'>: <function _rename>, <class 'sqlglot.expressions.Count'>: <function _rename>, <class 'sqlglot.expressions.CountIf'>: <function _rename>, <class 'sqlglot.expressions.CurrentDate'>: <function _rename>, <class 'sqlglot.expressions.CurrentDatetime'>: <function _rename>, <class 'sqlglot.expressions.CurrentTime'>: <function _rename>, <class 'sqlglot.expressions.CurrentTimestamp'>: <function _rename>, <class 'sqlglot.expressions.CurrentUser'>: <function _rename>, <class 'sqlglot.expressions.Date'>: <function _rename>, <class 'sqlglot.expressions.DateAdd'>: <function _rename>, <class 'sqlglot.expressions.DateDiff'>: <function _rename>, <class 'sqlglot.expressions.DateFromParts'>: <function _rename>, <class 'sqlglot.expressions.DateStrToDate'>: <function _rename>, <class 'sqlglot.expressions.DateSub'>: <function _rename>, <class 'sqlglot.expressions.DateToDateStr'>: <function _rename>, <class 'sqlglot.expressions.DateToDi'>: <function _rename>, <class 'sqlglot.expressions.DateTrunc'>: <function _rename>, <class 'sqlglot.expressions.DatetimeAdd'>: <function _rename>, <class 'sqlglot.expressions.DatetimeDiff'>: <function _rename>, <class 'sqlglot.expressions.DatetimeSub'>: <function _rename>, <class 'sqlglot.expressions.DatetimeTrunc'>: <function _rename>, <class 'sqlglot.expressions.Day'>: <function _rename>, <class 'sqlglot.expressions.DayOfMonth'>: <function _rename>, <class 'sqlglot.expressions.DayOfWeek'>: <function _rename>, <class 'sqlglot.expressions.DayOfYear'>: <function _rename>, <class 'sqlglot.expressions.Decode'>: <function _rename>, <class 'sqlglot.expressions.DiToDate'>: <function _rename>, <class 'sqlglot.expressions.Encode'>: <function _rename>, <class 'sqlglot.expressions.Exp'>: <function _rename>, <class 'sqlglot.expressions.Explode'>: <function _rename>, <class 'sqlglot.expressions.Extract'>: <function Python.Generator.<lambda>>, <class 'sqlglot.expressions.First'>: <function _rename>, <class 'sqlglot.expressions.Floor'>: <function _rename>, <class 'sqlglot.expressions.FromBase'>: <function _rename>, <class 'sqlglot.expressions.FromBase64'>: <function _rename>, <class 'sqlglot.expressions.GenerateSeries'>: <function _rename>, <class 'sqlglot.expressions.Greatest'>: <function _rename>, <class 'sqlglot.expressions.GroupConcat'>: <function _rename>, <class 'sqlglot.expressions.Hex'>: <function _rename>, <class 'sqlglot.expressions.Hll'>: <function _rename>, <class 'sqlglot.expressions.If'>: <function _rename>, <class 'sqlglot.expressions.Initcap'>: <function _rename>, <class 'sqlglot.expressions.IsNan'>: <function _rename>, <class 'sqlglot.expressions.JSONArray'>: <function _rename>, <class 'sqlglot.expressions.JSONArrayAgg'>: <function _rename>, <class 'sqlglot.expressions.JSONFormat'>: <function _rename>, <class 'sqlglot.expressions.JSONObject'>: <function _rename>, <class 'sqlglot.expressions.JSONTable'>: <function _rename>, <class 'sqlglot.expressions.Last'>: <function _rename>, <class 'sqlglot.expressions.LastDateOfMonth'>: <function _rename>, <class 'sqlglot.expressions.Least'>: <function _rename>, <class 'sqlglot.expressions.Left'>: <function _rename>, <class 'sqlglot.expressions.Length'>: <function _rename>, <class 'sqlglot.expressions.Levenshtein'>: <function _rename>, <class 'sqlglot.expressions.Ln'>: <function _rename>, <class 'sqlglot.expressions.Log'>: <function _rename>, <class 'sqlglot.expressions.Log10'>: <function _rename>, <class 'sqlglot.expressions.Log2'>: <function _rename>, <class 'sqlglot.expressions.LogicalAnd'>: <function _rename>, <class 'sqlglot.expressions.LogicalOr'>: <function _rename>, <class 'sqlglot.expressions.Lower'>: <function _rename>, <class 'sqlglot.expressions.MD5'>: <function _rename>, <class 'sqlglot.expressions.MD5Digest'>: <function _rename>, <class 'sqlglot.expressions.Map'>: <function _rename>, <class 'sqlglot.expressions.MapFromEntries'>: <function _rename>, <class 'sqlglot.expressions.MatchAgainst'>: <function _rename>, <class 'sqlglot.expressions.Max'>: <function _rename>, <class 'sqlglot.expressions.Min'>: <function _rename>, <class 'sqlglot.expressions.Month'>: <function _rename>, <class 'sqlglot.expressions.MonthsBetween'>: <function _rename>, <class 'sqlglot.expressions.NextValueFor'>: <function _rename>, <class 'sqlglot.expressions.NumberToStr'>: <function _rename>, <class 'sqlglot.expressions.Nvl2'>: <function _rename>, <class 'sqlglot.expressions.OpenJSON'>: <function _rename>, <class 'sqlglot.expressions.ParameterizedAgg'>: <function _rename>, <class 'sqlglot.expressions.ParseJSON'>: <function _rename>, <class 'sqlglot.expressions.PercentileCont'>: <function _rename>, <class 'sqlglot.expressions.PercentileDisc'>: <function _rename>, <class 'sqlglot.expressions.Posexplode'>: <function _rename>, <class 'sqlglot.expressions.Predict'>: <function _rename>, <class 'sqlglot.expressions.Quantile'>: <function _rename>, <class 'sqlglot.expressions.RangeN'>: <function _rename>, <class 'sqlglot.expressions.ReadCSV'>: <function _rename>, <class 'sqlglot.expressions.Reduce'>: <function _rename>, <class 'sqlglot.expressions.RegexpExtract'>: <function _rename>, <class 'sqlglot.expressions.RegexpILike'>: <function _rename>, <class 'sqlglot.expressions.RegexpReplace'>: <function _rename>, <class 'sqlglot.expressions.RegexpSplit'>: <function _rename>, <class 'sqlglot.expressions.Repeat'>: <function _rename>, <class 'sqlglot.expressions.Right'>: <function _rename>, <class 'sqlglot.expressions.Round'>: <function _rename>, <class 'sqlglot.expressions.RowNumber'>: <function _rename>, <class 'sqlglot.expressions.SHA'>: <function _rename>, <class 'sqlglot.expressions.SHA2'>: <function _rename>, <class 'sqlglot.expressions.SafeConcat'>: <function _rename>, <class 'sqlglot.expressions.SafeDivide'>: <function _rename>, <class 'sqlglot.expressions.SetAgg'>: <function _rename>, <class 'sqlglot.expressions.SortArray'>: <function _rename>, <class 'sqlglot.expressions.Split'>: <function _rename>, <class 'sqlglot.expressions.Sqrt'>: <function _rename>, <class 'sqlglot.expressions.StandardHash'>: <function _rename>, <class 'sqlglot.expressions.StarMap'>: <function _rename>, <class 'sqlglot.expressions.StartsWith'>: <function _rename>, <class 'sqlglot.expressions.Stddev'>: <function _rename>, <class 'sqlglot.expressions.StddevPop'>: <function _rename>, <class 'sqlglot.expressions.StddevSamp'>: <function _rename>, <class 'sqlglot.expressions.StrPosition'>: <function _rename>, <class 'sqlglot.expressions.StrToDate'>: <function _rename>, <class 'sqlglot.expressions.StrToMap'>: <function _rename>, <class 'sqlglot.expressions.StrToTime'>: <function _rename>, <class 'sqlglot.expressions.StrToUnix'>: <function _rename>, <class 'sqlglot.expressions.Struct'>: <function _rename>, <class 'sqlglot.expressions.StructExtract'>: <function _rename>, <class 'sqlglot.expressions.Stuff'>: <function _rename>, <class 'sqlglot.expressions.Substring'>: <function _rename>, <class 'sqlglot.expressions.Sum'>: <function _rename>, <class 'sqlglot.expressions.TimeAdd'>: <function _rename>, <class 'sqlglot.expressions.TimeDiff'>: <function _rename>, <class 'sqlglot.expressions.TimeStrToDate'>: <function _rename>, <class 'sqlglot.expressions.TimeStrToTime'>: <function _rename>, <class 'sqlglot.expressions.TimeStrToUnix'>: <function _rename>, <class 'sqlglot.expressions.TimeSub'>: <function _rename>, <class 'sqlglot.expressions.TimeToStr'>: <function _rename>, <class 'sqlglot.expressions.TimeToTimeStr'>: <function _rename>, <class 'sqlglot.expressions.TimeToUnix'>: <function _rename>, <class 'sqlglot.expressions.TimeTrunc'>: <function _rename>, <class 'sqlglot.expressions.Timestamp'>: <function _rename>, <class 'sqlglot.expressions.TimestampAdd'>: <function _rename>, <class 'sqlglot.expressions.TimestampDiff'>: <function _rename>, <class 'sqlglot.expressions.TimestampSub'>: <function _rename>, <class 'sqlglot.expressions.TimestampTrunc'>: <function _rename>, <class 'sqlglot.expressions.ToBase64'>: <function _rename>, <class 'sqlglot.expressions.ToChar'>: <function _rename>, <class 'sqlglot.expressions.ToDays'>: <function _rename>, <class 'sqlglot.expressions.Transform'>: <function _rename>, <class 'sqlglot.expressions.Trim'>: <function _rename>, <class 'sqlglot.expressions.TryCast'>: <function _rename>, <class 'sqlglot.expressions.TsOrDiToDi'>: <function _rename>, <class 'sqlglot.expressions.TsOrDsAdd'>: <function _rename>, <class 'sqlglot.expressions.TsOrDsToDate'>: <function _rename>, <class 'sqlglot.expressions.TsOrDsToDateStr'>: <function _rename>, <class 'sqlglot.expressions.Unhex'>: <function _rename>, <class 'sqlglot.expressions.UnixToStr'>: <function _rename>, <class 'sqlglot.expressions.UnixToTime'>: <function _rename>, <class 'sqlglot.expressions.UnixToTimeStr'>: <function _rename>, <class 'sqlglot.expressions.Upper'>: <function _rename>, <class 'sqlglot.expressions.VarMap'>: <function _rename>, <class 'sqlglot.expressions.Variance'>: <function _rename>, <class 'sqlglot.expressions.VariancePop'>: <function _rename>, <class 'sqlglot.expressions.Week'>: <function _rename>, <class 'sqlglot.expressions.WeekOfYear'>: <function _rename>, <class 'sqlglot.expressions.When'>: <function _rename>, <class 'sqlglot.expressions.XMLTable'>: <function _rename>, <class 'sqlglot.expressions.Year'>: <function _rename>, <class 'sqlglot.expressions.Alias'>: <function Python.Generator.<lambda>>, <class 'sqlglot.expressions.Between'>: <function _rename>, <class 'sqlglot.expressions.Boolean'>: <function Python.Generator.<lambda>>, <class 'sqlglot.expressions.Column'>: <function Python.Generator.<lambda>>, <class 'sqlglot.expressions.Distinct'>: <function Python.Generator.<lambda>>, <class 'sqlglot.expressions.In'>: <function Python.Generator.<lambda>>, <class 'sqlglot.expressions.Interval'>: <function Python.Generator.<lambda>>, <class 'sqlglot.expressions.Lambda'>: <function _lambda_sql>, <class 'sqlglot.expressions.Not'>: <function Python.Generator.<lambda>>, <class 'sqlglot.expressions.Null'>: <function Python.Generator.<lambda>>, <class 'sqlglot.expressions.Ordered'>: <function _ordered_py>, <class 'sqlglot.expressions.Star'>: <function Python.Generator.<lambda>>}
SELECT_KINDS: Tuple[str, ...] = ()
INVERSE_TIME_MAPPING: Dict[str, str] = {}
INVERSE_TIME_TRIE: Dict = {}
INVERSE_ESCAPE_SEQUENCES: Dict[str, str] = {}
@classmethod
def can_identify(text: str, identify: str | bool = 'safe') -> bool: View Source

    279    @classmethod
    280    def can_identify(cls, text: str, identify: str | bool = "safe") -> bool:
    281        """Checks if text can be identified given an identify option.
    282
    283        Args:
    284            text: The text to check.
    285            identify:
    286                "always" or `True`: Always returns true.
    287                "safe": True if the identifier is case-insensitive.
    288
    289        Returns:
    290            Whether or not the given text can be identified.
    291        """
    292        if identify is True or identify == "always":
    293            return True
    294
    295        if identify == "safe":
    296            return not cls.case_sensitive(text)
    297
    298        return False

Checks if text can be identified given an identify option.

###### Arguments:

- text: The text to check.
- identify: "always" or `True`: Always returns true. "safe": True if the identifier is case-insensitive.

###### Returns:

> Whether or not the given text can be identified.

QUOTE_START = "'"
QUOTE_END = "'"
IDENTIFIER_START = '"'
IDENTIFIER_END = '"'
TOKENIZER_CLASS = <class 'Python.Tokenizer'>
BIT_START: Optional[str] = None
BIT_END: Optional[str] = None
HEX_START: Optional[str] = None
HEX_END: Optional[str] = None
BYTE_START: Optional[str] = None
BYTE_END: Optional[str] = None

##### Inherited Members

sqlglot.generator.Generator
  Generator
  LOG_BASE_FIRST
  NULL_ORDERING_SUPPORTED
  LOCKING_READS_SUPPORTED
  EXPLICIT_UNION
  WRAP_DERIVED_VALUES
  CREATE_FUNCTION_RETURN_AS
  MATCHED_BY_SOURCE
  SINGLE_STRING_INTERVAL
  INTERVAL_ALLOWS_PLURAL_FORM
  TABLESAMPLE_WITH_METHOD
  TABLESAMPLE_SIZE_IS_PERCENT
  LIMIT_FETCH
  RENAME_TABLE_WITH_DB
  GROUPINGS_SEP
  INDEX_ON
  JOIN_HINTS
  TABLE_HINTS
  QUERY_HINTS
  QUERY_HINT_SEP
  IS_BOOL_ALLOWED
  DUPLICATE_KEY_UPDATE_WITH_SET
  LIMIT_IS_TOP
  RETURNING_END
  COLUMN_JOIN_MARKS_SUPPORTED
  EXTRACT_ALLOWS_QUOTES
  TZ_TO_WITH_TIME_ZONE
  NVL2_SUPPORTED
  VALUES_AS_TABLE
  ALTER_TABLE_ADD_COLUMN_KEYWORD
  UNNEST_WITH_ORDINALITY
  AGGREGATE_FILTER_SUPPORTED
  SEMI_ANTI_JOIN_WITH_SIDE
  SUPPORTS_PARAMETERS
  COMPUTED_COLUMN_WITH_TYPE
  SUPPORTS_TABLE_COPY
  TABLESAMPLE_REQUIRES_PARENS
  COLLATE_IS_FUNC
  DATA_TYPE_SPECIFIERS_ALLOWED
  TYPE_MAPPING
  STAR_MAPPING
  TIME_PART_SINGULARS
  TOKEN_MAPPING
  STRUCT_DELIMITER
  PARAMETER_TOKEN
  PROPERTIES_LOCATION
  RESERVED_KEYWORDS
  WITH_SEPARATED_COMMENTS
  UNWRAPPED_INTERVAL_VALUES
  SENTINEL_LINE_BREAK
  INDEX_OFFSET
  UNNEST_COLUMN_ONLY
  ALIAS_POST_TABLESAMPLE
  IDENTIFIERS_CAN_START_WITH_DIGIT
  STRICT_STRING_CONCAT
  NORMALIZE_FUNCTIONS
  NULL_ORDERING
  pretty
  identify
  normalize
  pad
  unsupported_level
  max_unsupported
  leading_comma
  max_text_width
  comments
  normalize_functions
  unsupported_messages
  generate
  unsupported
  sep
  seg
  pad_comment
  maybe_comment
  wrap
  no_identify
  normalize_func
  indent
  sql
  uncache_sql
  cache_sql
  characterset_sql
  column_sql
  columnposition_sql
  columndef_sql
  columnconstraint_sql
  computedcolumnconstraint_sql
  autoincrementcolumnconstraint_sql
  compresscolumnconstraint_sql
  generatedasidentitycolumnconstraint_sql
  notnullcolumnconstraint_sql
  primarykeycolumnconstraint_sql
  uniquecolumnconstraint_sql
  createable_sql
  create_sql
  clone_sql
  describe_sql
  prepend_ctes
  with_sql
  cte_sql
  tablealias_sql
  bitstring_sql
  hexstring_sql
  bytestring_sql
  rawstring_sql
  datatypeparam_sql
  datatype_sql
  directory_sql
  delete_sql
  drop_sql
  except_sql
  except_op
  fetch_sql
  filter_sql
  hint_sql
  index_sql
  identifier_sql
  inputoutputformat_sql
  national_sql
  partition_sql
  properties_sql
  root_properties
  properties
  with_properties
  locate_properties
  property_name
  property_sql
  likeproperty_sql
  fallbackproperty_sql
  journalproperty_sql
  freespaceproperty_sql
  checksumproperty_sql
  mergeblockratioproperty_sql
  datablocksizeproperty_sql
  blockcompressionproperty_sql
  isolatedloadingproperty_sql
  lockingproperty_sql
  withdataproperty_sql
  insert_sql
  intersect_sql
  intersect_op
  introducer_sql
  kill_sql
  pseudotype_sql
  objectidentifier_sql
  onconflict_sql
  returning_sql
  rowformatdelimitedproperty_sql
  withtablehint_sql
  indextablehint_sql
  table_sql
  tablesample_sql
  pivot_sql
  version_sql
  tuple_sql
  update_sql
  values_sql
  var_sql
  into_sql
  from_sql
  group_sql
  having_sql
  connect_sql
  prior_sql
  join_sql
  lambda_sql
  lateral_sql
  limit_sql
  offset_sql
  setitem_sql
  set_sql
  pragma_sql
  lock_sql
  literal_sql
  escape_str
  loaddata_sql
  null_sql
  boolean_sql
  order_sql
  cluster_sql
  distribute_sql
  sort_sql
  ordered_sql
  matchrecognize_sql
  query_modifiers
  offset_limit_modifiers
  after_having_modifiers
  after_limit_modifiers
  select_sql
  schema_sql
  schema_columns_sql
  star_sql
  parameter_sql
  sessionparameter_sql
  placeholder_sql
  subquery_sql
  qualify_sql
  union_sql
  union_op
  unnest_sql
  where_sql
  window_sql
  partition_by_sql
  windowspec_sql
  withingroup_sql
  between_sql
  bracket_sql
  safebracket_sql
  all_sql
  any_sql
  exists_sql
  case_sql
  constraint_sql
  nextvaluefor_sql
  extract_sql
  trim_sql
  safeconcat_sql
  check_sql
  foreignkey_sql
  primarykey_sql
  if_sql
  matchagainst_sql
  jsonkeyvalue_sql
  formatjson_sql
  jsonobject_sql
  jsonarray_sql
  jsonarrayagg_sql
  jsoncolumndef_sql
  jsontable_sql
  openjsoncolumndef_sql
  openjson_sql
  in_sql
  in_unnest_op
  interval_sql
  return_sql
  reference_sql
  anonymous_sql
  paren_sql
  neg_sql
  not_sql
  alias_sql
  aliases_sql
  attimezone_sql
  add_sql
  and_sql
  xor_sql
  connector_sql
  bitwiseand_sql
  bitwiseleftshift_sql
  bitwisenot_sql
  bitwiseor_sql
  bitwiserightshift_sql
  bitwisexor_sql
  cast_sql
  currentdate_sql
  collate_sql
  command_sql
  comment_sql
  mergetreettlaction_sql
  mergetreettl_sql
  transaction_sql
  commit_sql
  rollback_sql
  altercolumn_sql
  renametable_sql
  altertable_sql
  droppartition_sql
  addconstraint_sql
  distinct_sql
  ignorenulls_sql
  respectnulls_sql
  intdiv_sql
  dpipe_sql
  safedpipe_sql
  div_sql
  overlaps_sql
  distance_sql
  dot_sql
  eq_sql
  escape_sql
  glob_sql
  gt_sql
  gte_sql
  ilike_sql
  ilikeany_sql
  is_sql
  like_sql
  likeany_sql
  similarto_sql
  lt_sql
  lte_sql
  mod_sql
  mul_sql
  neq_sql
  nullsafeeq_sql
  nullsafeneq_sql
  or_sql
  slice_sql
  sub_sql
  trycast_sql
  log_sql
  use_sql
  binary
  function_fallback_sql
  func
  format_args
  text_width
  format_time
  expressions
  op_expressions
  naked_property
  set_operation
  tag_sql
  token_sql
  userdefinedfunction_sql
  joinhint_sql
  kwarg_sql
  when_sql
  merge_sql
  tochar_sql
  dictproperty_sql
  dictrange_sql
  dictsubproperty_sql
  oncluster_sql
  clusteredbyproperty_sql
  anyvalue_sql
  querytransform_sql
  indexconstraintoption_sql
  indexcolumnconstraint_sql
  nvl2_sql
  comprehension_sql
  columnprefix_sql
  opclass_sql
  predict_sql