sqlglot.jsonpath API documentation

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# sqlglot.jsonpath

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      1from __future__ import annotations
      2
      3import typing as t
      4
      5import sqlglot.expressions as exp
      6from sqlglot.errors import ParseError
      7from sqlglot.tokens import Token, Tokenizer, TokenType
      8
      9if t.TYPE_CHECKING:
     10    from sqlglot._typing import Lit
     11
     12
     13class JSONPathTokenizer(Tokenizer):
     14    SINGLE_TOKENS = {
     15        "(": TokenType.L_PAREN,
     16        ")": TokenType.R_PAREN,
     17        "[": TokenType.L_BRACKET,
     18        "]": TokenType.R_BRACKET,
     19        ":": TokenType.COLON,
     20        ",": TokenType.COMMA,
     21        "-": TokenType.DASH,
     22        ".": TokenType.DOT,
     23        "?": TokenType.PLACEHOLDER,
     24        "@": TokenType.PARAMETER,
     25        "'": TokenType.QUOTE,
     26        '"': TokenType.QUOTE,
     27        "$": TokenType.DOLLAR,
     28        "*": TokenType.STAR,
     29    }
     30
     31    KEYWORDS = {
     32        "..": TokenType.DOT,
     33    }
     34
     35    IDENTIFIER_ESCAPES = ["\\"]
     36    STRING_ESCAPES = ["\\"]
     37
     38
     39def parse(path: str) -> exp.JSONPath:
     40    """Takes in a JSON path string and parses it into a JSONPath expression."""
     41    tokens = JSONPathTokenizer().tokenize(path)
     42    size = len(tokens)
     43
     44    i = 0
     45
     46    def _curr() -> t.Optional[TokenType]:
     47        return tokens[i].token_type if i < size else None
     48
     49    def _prev() -> Token:
     50        return tokens[i - 1]
     51
     52    def _advance() -> Token:
     53        nonlocal i
     54        i += 1
     55        return _prev()
     56
     57    def _error(msg: str) -> str:
     58        return f"{msg} at index {i}: {path}"
     59
     60    @t.overload
     61    def _match(token_type: TokenType, raise_unmatched: Lit[True] = True) -> Token:
     62        pass
     63
     64    @t.overload
     65    def _match(token_type: TokenType, raise_unmatched: Lit[False] = False) -> t.Optional[Token]:
     66        pass
     67
     68    def _match(token_type, raise_unmatched=False):
     69        if _curr() == token_type:
     70            return _advance()
     71        if raise_unmatched:
     72            raise ParseError(_error(f"Expected {token_type}"))
     73        return None
     74
     75    def _parse_literal() -> t.Any:
     76        token = _match(TokenType.STRING) or _match(TokenType.IDENTIFIER)
     77        if token:
     78            return token.text
     79        if _match(TokenType.STAR):
     80            return exp.JSONPathWildcard()
     81        if _match(TokenType.PLACEHOLDER) or _match(TokenType.L_PAREN):
     82            script = _prev().text == "("
     83            start = i
     84
     85            while True:
     86                if _match(TokenType.L_BRACKET):
     87                    _parse_bracket()  # nested call which we can throw away
     88                if _curr() in (TokenType.R_BRACKET, None):
     89                    break
     90                _advance()
     91
     92            expr_type = exp.JSONPathScript if script else exp.JSONPathFilter
     93            return expr_type(this=path[tokens[start].start : tokens[i].end])
     94
     95        number = "-" if _match(TokenType.DASH) else ""
     96
     97        token = _match(TokenType.NUMBER)
     98        if token:
     99            number += token.text
    100
    101        if number:
    102            return int(number)
    103
    104        return False
    105
    106    def _parse_slice() -> t.Any:
    107        start = _parse_literal()
    108        end = _parse_literal() if _match(TokenType.COLON) else None
    109        step = _parse_literal() if _match(TokenType.COLON) else None
    110
    111        if end is None and step is None:
    112            return start
    113
    114        return exp.JSONPathSlice(start=start, end=end, step=step)
    115
    116    def _parse_bracket() -> exp.JSONPathPart:
    117        literal = _parse_slice()
    118
    119        if isinstance(literal, str) or literal is not False:
    120            indexes = [literal]
    121            while _match(TokenType.COMMA):
    122                literal = _parse_slice()
    123
    124                if literal:
    125                    indexes.append(literal)
    126
    127            if len(indexes) == 1:
    128                if isinstance(literal, str):
    129                    node: exp.JSONPathPart = exp.JSONPathKey(this=indexes[0])
    130                elif isinstance(literal, exp.JSONPathPart) and isinstance(
    131                    literal, (exp.JSONPathScript, exp.JSONPathFilter)
    132                ):
    133                    node = exp.JSONPathSelector(this=indexes[0])
    134                else:
    135                    node = exp.JSONPathSubscript(this=indexes[0])
    136            else:
    137                node = exp.JSONPathUnion(expressions=indexes)
    138        else:
    139            raise ParseError(_error("Cannot have empty segment"))
    140
    141        _match(TokenType.R_BRACKET, raise_unmatched=True)
    142
    143        return node
    144
    145    # We canonicalize the JSON path AST so that it always starts with a
    146    # "root" element, so paths like "field" will be generated as "$.field"
    147    _match(TokenType.DOLLAR)
    148    expressions: t.List[exp.JSONPathPart] = [exp.JSONPathRoot()]
    149
    150    while _curr():
    151        if _match(TokenType.DOT) or _match(TokenType.COLON):
    152            recursive = _prev().text == ".."
    153
    154            if _match(TokenType.VAR) or _match(TokenType.IDENTIFIER):
    155                value: t.Optional[str | exp.JSONPathWildcard] = _prev().text
    156            elif _match(TokenType.STAR):
    157                value = exp.JSONPathWildcard()
    158            else:
    159                value = None
    160
    161            if recursive:
    162                expressions.append(exp.JSONPathRecursive(this=value))
    163            elif value:
    164                expressions.append(exp.JSONPathKey(this=value))
    165            else:
    166                raise ParseError(_error("Expected key name or * after DOT"))
    167        elif _match(TokenType.L_BRACKET):
    168            expressions.append(_parse_bracket())
    169        elif _match(TokenType.VAR) or _match(TokenType.IDENTIFIER):
    170            expressions.append(exp.JSONPathKey(this=_prev().text))
    171        elif _match(TokenType.STAR):
    172            expressions.append(exp.JSONPathWildcard())
    173        else:
    174            raise ParseError(_error(f"Unexpected {tokens[i].token_type}"))
    175
    176    return exp.JSONPath(expressions=expressions)
    177
    178
    179JSON_PATH_PART_TRANSFORMS: t.Dict[t.Type[exp.Expression], t.Callable[..., str]] = {
    180    exp.JSONPathFilter: lambda _, e: f"?{e.this}",
    181    exp.JSONPathKey: lambda self, e: self._jsonpathkey_sql(e),
    182    exp.JSONPathRecursive: lambda _, e: f"..{e.this or ''}",
    183    exp.JSONPathRoot: lambda *_: "$",
    184    exp.JSONPathScript: lambda _, e: f"({e.this}",
    185    exp.JSONPathSelector: lambda self, e: f"[{self.json_path_part(e.this)}]",
    186    exp.JSONPathSlice: lambda self, e: ":".join(
    187        "" if p is False else self.json_path_part(p)
    188        for p in [e.args.get("start"), e.args.get("end"), e.args.get("step")]
    189        if p is not None
    190    ),
    191    exp.JSONPathSubscript: lambda self, e: self._jsonpathsubscript_sql(e),
    192    exp.JSONPathUnion: lambda self,
    193    e: f"[{','.join(self.json_path_part(p) for p in e.expressions)}]",
    194    exp.JSONPathWildcard: lambda *_: "*",
    195}
    196
    197ALL_JSON_PATH_PARTS = set(JSON_PATH_PART_TRANSFORMS)

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

    14class JSONPathTokenizer(Tokenizer):
    15    SINGLE_TOKENS = {
    16        "(": TokenType.L_PAREN,
    17        ")": TokenType.R_PAREN,
    18        "[": TokenType.L_BRACKET,
    19        "]": TokenType.R_BRACKET,
    20        ":": TokenType.COLON,
    21        ",": TokenType.COMMA,
    22        "-": TokenType.DASH,
    23        ".": TokenType.DOT,
    24        "?": TokenType.PLACEHOLDER,
    25        "@": TokenType.PARAMETER,
    26        "'": TokenType.QUOTE,
    27        '"': TokenType.QUOTE,
    28        "$": TokenType.DOLLAR,
    29        "*": TokenType.STAR,
    30    }
    31
    32    KEYWORDS = {
    33        "..": TokenType.DOT,
    34    }
    35
    36    IDENTIFIER_ESCAPES = ["\\"]
    37    STRING_ESCAPES = ["\\"]

SINGLE_TOKENS = {'(': <TokenType.L_PAREN: 'L_PAREN'>, ')': <TokenType.R_PAREN: 'R_PAREN'>, '[': <TokenType.L_BRACKET: 'L_BRACKET'>, ']': <TokenType.R_BRACKET: 'R_BRACKET'>, ':': <TokenType.COLON: 'COLON'>, ',': <TokenType.COMMA: 'COMMA'>, '-': <TokenType.DASH: 'DASH'>, '.': <TokenType.DOT: 'DOT'>, '?': <TokenType.PLACEHOLDER: 'PLACEHOLDER'>, '@': <TokenType.PARAMETER: 'PARAMETER'>, "'": <TokenType.QUOTE: 'QUOTE'>, '"': <TokenType.QUOTE: 'QUOTE'>, '$': <TokenType.DOLLAR: 'DOLLAR'>, '*': <TokenType.STAR: 'STAR'>}
KEYWORDS = {'..': <TokenType.DOT: 'DOT'>}
IDENTIFIER_ESCAPES = ['\\']
STRING_ESCAPES = ['\\']

##### Inherited Members

sqlglot.tokens.Tokenizer
  Tokenizer
  BIT_STRINGS
  BYTE_STRINGS
  HEX_STRINGS
  RAW_STRINGS
  HEREDOC_STRINGS
  UNICODE_STRINGS
  IDENTIFIERS
  QUOTES
  VAR_SINGLE_TOKENS
  HEREDOC_TAG_IS_IDENTIFIER
  HEREDOC_STRING_ALTERNATIVE
  WHITE_SPACE
  COMMANDS
  COMMAND_PREFIX_TOKENS
  NUMERIC_LITERALS
  COMMENTS
  dialect
  reset
  tokenize
  peek
  tokenize_rs
  size
  sql
  tokens

def parse(path: str) -> sqlglot.expressions.JSONPath: View Source

     40def parse(path: str) -> exp.JSONPath:
     41    """Takes in a JSON path string and parses it into a JSONPath expression."""
     42    tokens = JSONPathTokenizer().tokenize(path)
     43    size = len(tokens)
     44
     45    i = 0
     46
     47    def _curr() -> t.Optional[TokenType]:
     48        return tokens[i].token_type if i < size else None
     49
     50    def _prev() -> Token:
     51        return tokens[i - 1]
     52
     53    def _advance() -> Token:
     54        nonlocal i
     55        i += 1
     56        return _prev()
     57
     58    def _error(msg: str) -> str:
     59        return f"{msg} at index {i}: {path}"
     60
     61    @t.overload
     62    def _match(token_type: TokenType, raise_unmatched: Lit[True] = True) -> Token:
     63        pass
     64
     65    @t.overload
     66    def _match(token_type: TokenType, raise_unmatched: Lit[False] = False) -> t.Optional[Token]:
     67        pass
     68
     69    def _match(token_type, raise_unmatched=False):
     70        if _curr() == token_type:
     71            return _advance()
     72        if raise_unmatched:
     73            raise ParseError(_error(f"Expected {token_type}"))
     74        return None
     75
     76    def _parse_literal() -> t.Any:
     77        token = _match(TokenType.STRING) or _match(TokenType.IDENTIFIER)
     78        if token:
     79            return token.text
     80        if _match(TokenType.STAR):
     81            return exp.JSONPathWildcard()
     82        if _match(TokenType.PLACEHOLDER) or _match(TokenType.L_PAREN):
     83            script = _prev().text == "("
     84            start = i
     85
     86            while True:
     87                if _match(TokenType.L_BRACKET):
     88                    _parse_bracket()  # nested call which we can throw away
     89                if _curr() in (TokenType.R_BRACKET, None):
     90                    break
     91                _advance()
     92
     93            expr_type = exp.JSONPathScript if script else exp.JSONPathFilter
     94            return expr_type(this=path[tokens[start].start : tokens[i].end])
     95
     96        number = "-" if _match(TokenType.DASH) else ""
     97
     98        token = _match(TokenType.NUMBER)
     99        if token:
    100            number += token.text
    101
    102        if number:
    103            return int(number)
    104
    105        return False
    106
    107    def _parse_slice() -> t.Any:
    108        start = _parse_literal()
    109        end = _parse_literal() if _match(TokenType.COLON) else None
    110        step = _parse_literal() if _match(TokenType.COLON) else None
    111
    112        if end is None and step is None:
    113            return start
    114
    115        return exp.JSONPathSlice(start=start, end=end, step=step)
    116
    117    def _parse_bracket() -> exp.JSONPathPart:
    118        literal = _parse_slice()
    119
    120        if isinstance(literal, str) or literal is not False:
    121            indexes = [literal]
    122            while _match(TokenType.COMMA):
    123                literal = _parse_slice()
    124
    125                if literal:
    126                    indexes.append(literal)
    127
    128            if len(indexes) == 1:
    129                if isinstance(literal, str):
    130                    node: exp.JSONPathPart = exp.JSONPathKey(this=indexes[0])
    131                elif isinstance(literal, exp.JSONPathPart) and isinstance(
    132                    literal, (exp.JSONPathScript, exp.JSONPathFilter)
    133                ):
    134                    node = exp.JSONPathSelector(this=indexes[0])
    135                else:
    136                    node = exp.JSONPathSubscript(this=indexes[0])
    137            else:
    138                node = exp.JSONPathUnion(expressions=indexes)
    139        else:
    140            raise ParseError(_error("Cannot have empty segment"))
    141
    142        _match(TokenType.R_BRACKET, raise_unmatched=True)
    143
    144        return node
    145
    146    # We canonicalize the JSON path AST so that it always starts with a
    147    # "root" element, so paths like "field" will be generated as "$.field"
    148    _match(TokenType.DOLLAR)
    149    expressions: t.List[exp.JSONPathPart] = [exp.JSONPathRoot()]
    150
    151    while _curr():
    152        if _match(TokenType.DOT) or _match(TokenType.COLON):
    153            recursive = _prev().text == ".."
    154
    155            if _match(TokenType.VAR) or _match(TokenType.IDENTIFIER):
    156                value: t.Optional[str | exp.JSONPathWildcard] = _prev().text
    157            elif _match(TokenType.STAR):
    158                value = exp.JSONPathWildcard()
    159            else:
    160                value = None
    161
    162            if recursive:
    163                expressions.append(exp.JSONPathRecursive(this=value))
    164            elif value:
    165                expressions.append(exp.JSONPathKey(this=value))
    166            else:
    167                raise ParseError(_error("Expected key name or * after DOT"))
    168        elif _match(TokenType.L_BRACKET):
    169            expressions.append(_parse_bracket())
    170        elif _match(TokenType.VAR) or _match(TokenType.IDENTIFIER):
    171            expressions.append(exp.JSONPathKey(this=_prev().text))
    172        elif _match(TokenType.STAR):
    173            expressions.append(exp.JSONPathWildcard())
    174        else:
    175            raise ParseError(_error(f"Unexpected {tokens[i].token_type}"))
    176
    177    return exp.JSONPath(expressions=expressions)

Takes in a JSON path string and parses it into a JSONPath expression.

JSON_PATH_PART_TRANSFORMS: Dict[Type[sqlglot.expressions.Expression], Callable[..., str]] = {<class 'sqlglot.expressions.JSONPathFilter'>: <function <lambda>>, <class 'sqlglot.expressions.JSONPathKey'>: <function <lambda>>, <class 'sqlglot.expressions.JSONPathRecursive'>: <function <lambda>>, <class 'sqlglot.expressions.JSONPathRoot'>: <function <lambda>>, <class 'sqlglot.expressions.JSONPathScript'>: <function <lambda>>, <class 'sqlglot.expressions.JSONPathSelector'>: <function <lambda>>, <class 'sqlglot.expressions.JSONPathSlice'>: <function <lambda>>, <class 'sqlglot.expressions.JSONPathSubscript'>: <function <lambda>>, <class 'sqlglot.expressions.JSONPathUnion'>: <function <lambda>>, <class 'sqlglot.expressions.JSONPathWildcard'>: <function <lambda>>}
ALL_JSON_PATH_PARTS = {<class 'sqlglot.expressions.JSONPathSelector'>, <class 'sqlglot.expressions.JSONPathSlice'>, <class 'sqlglot.expressions.JSONPathUnion'>, <class 'sqlglot.expressions.JSONPathScript'>, <class 'sqlglot.expressions.JSONPathRoot'>, <class 'sqlglot.expressions.JSONPathRecursive'>, <class 'sqlglot.expressions.JSONPathKey'>, <class 'sqlglot.expressions.JSONPathWildcard'>, <class 'sqlglot.expressions.JSONPathFilter'>, <class 'sqlglot.expressions.JSONPathSubscript'>}