src/black/mode.py

   1 """Data structures configuring Black behavior.
   2
   3 Mostly around Python language feature support per version and Black configuration
   4 chosen by the user.
   5 """
   6
   7 import sys
   8
   9 from dataclasses import dataclass, field
  10 from enum import Enum
  11 from operator import attrgetter
  12 from typing import Dict, Set
  13
  14 if sys.version_info < (3, 8):
  15     from typing_extensions import Final
  16 else:
  17     from typing import Final
  18
  19 from black.const import DEFAULT_LINE_LENGTH
  20
  21
  22 class TargetVersion(Enum):
  23     PY27 = 2
  24     PY33 = 3
  25     PY34 = 4
  26     PY35 = 5
  27     PY36 = 6
  28     PY37 = 7
  29     PY38 = 8
  30     PY39 = 9
  31     PY310 = 10
  32
  33     def is_python2(self) -> bool:
  34         return self is TargetVersion.PY27
  35
  36
  37 class Feature(Enum):
  38     # All string literals are unicode
  39     UNICODE_LITERALS = 1
  40     F_STRINGS = 2
  41     NUMERIC_UNDERSCORES = 3
  42     TRAILING_COMMA_IN_CALL = 4
  43     TRAILING_COMMA_IN_DEF = 5
  44     # The following two feature-flags are mutually exclusive, and exactly one should be
  45     # set for every version of python.
  46     ASYNC_IDENTIFIERS = 6
  47     ASYNC_KEYWORDS = 7
  48     ASSIGNMENT_EXPRESSIONS = 8
  49     POS_ONLY_ARGUMENTS = 9
  50     RELAXED_DECORATORS = 10
  51     PATTERN_MATCHING = 11
  52     FORCE_OPTIONAL_PARENTHESES = 50
  53
  54     # __future__ flags
  55     FUTURE_ANNOTATIONS = 51
  56
  57     # temporary for Python 2 deprecation
  58     PRINT_STMT = 200
  59     EXEC_STMT = 201
  60     AUTOMATIC_PARAMETER_UNPACKING = 202
  61     COMMA_STYLE_EXCEPT = 203
  62     COMMA_STYLE_RAISE = 204
  63     LONG_INT_LITERAL = 205
  64     OCTAL_INT_LITERAL = 206
  65     BACKQUOTE_REPR = 207
  66
  67
  68 FUTURE_FLAG_TO_FEATURE: Final = {
  69     "annotations": Feature.FUTURE_ANNOTATIONS,
  70 }
  71
  72
  73 VERSION_TO_FEATURES: Dict[TargetVersion, Set[Feature]] = {
  74     TargetVersion.PY27: {
  75         Feature.ASYNC_IDENTIFIERS,
  76         Feature.PRINT_STMT,
  77         Feature.EXEC_STMT,
  78         Feature.AUTOMATIC_PARAMETER_UNPACKING,
  79         Feature.COMMA_STYLE_EXCEPT,
  80         Feature.COMMA_STYLE_RAISE,
  81         Feature.LONG_INT_LITERAL,
  82         Feature.OCTAL_INT_LITERAL,
  83         Feature.BACKQUOTE_REPR,
  84     },
  85     TargetVersion.PY33: {Feature.UNICODE_LITERALS, Feature.ASYNC_IDENTIFIERS},
  86     TargetVersion.PY34: {Feature.UNICODE_LITERALS, Feature.ASYNC_IDENTIFIERS},
  87     TargetVersion.PY35: {
  88         Feature.UNICODE_LITERALS,
  89         Feature.TRAILING_COMMA_IN_CALL,
  90         Feature.ASYNC_IDENTIFIERS,
  91     },
  92     TargetVersion.PY36: {
  93         Feature.UNICODE_LITERALS,
  94         Feature.F_STRINGS,
  95         Feature.NUMERIC_UNDERSCORES,
  96         Feature.TRAILING_COMMA_IN_CALL,
  97         Feature.TRAILING_COMMA_IN_DEF,
  98         Feature.ASYNC_IDENTIFIERS,
  99     },
 100     TargetVersion.PY37: {
 101         Feature.UNICODE_LITERALS,
 102         Feature.F_STRINGS,
 103         Feature.NUMERIC_UNDERSCORES,
 104         Feature.TRAILING_COMMA_IN_CALL,
 105         Feature.TRAILING_COMMA_IN_DEF,
 106         Feature.ASYNC_KEYWORDS,
 107         Feature.FUTURE_ANNOTATIONS,
 108     },
 109     TargetVersion.PY38: {
 110         Feature.UNICODE_LITERALS,
 111         Feature.F_STRINGS,
 112         Feature.NUMERIC_UNDERSCORES,
 113         Feature.TRAILING_COMMA_IN_CALL,
 114         Feature.TRAILING_COMMA_IN_DEF,
 115         Feature.ASYNC_KEYWORDS,
 116         Feature.FUTURE_ANNOTATIONS,
 117         Feature.ASSIGNMENT_EXPRESSIONS,
 118         Feature.POS_ONLY_ARGUMENTS,
 119     },
 120     TargetVersion.PY39: {
 121         Feature.UNICODE_LITERALS,
 122         Feature.F_STRINGS,
 123         Feature.NUMERIC_UNDERSCORES,
 124         Feature.TRAILING_COMMA_IN_CALL,
 125         Feature.TRAILING_COMMA_IN_DEF,
 126         Feature.ASYNC_KEYWORDS,
 127         Feature.FUTURE_ANNOTATIONS,
 128         Feature.ASSIGNMENT_EXPRESSIONS,
 129         Feature.RELAXED_DECORATORS,
 130         Feature.POS_ONLY_ARGUMENTS,
 131     },
 132     TargetVersion.PY310: {
 133         Feature.UNICODE_LITERALS,
 134         Feature.F_STRINGS,
 135         Feature.NUMERIC_UNDERSCORES,
 136         Feature.TRAILING_COMMA_IN_CALL,
 137         Feature.TRAILING_COMMA_IN_DEF,
 138         Feature.ASYNC_KEYWORDS,
 139         Feature.FUTURE_ANNOTATIONS,
 140         Feature.ASSIGNMENT_EXPRESSIONS,
 141         Feature.RELAXED_DECORATORS,
 142         Feature.POS_ONLY_ARGUMENTS,
 143         Feature.PATTERN_MATCHING,
 144     },
 145 }
 146
 147
 148 def supports_feature(target_versions: Set[TargetVersion], feature: Feature) -> bool:
 149     return all(feature in VERSION_TO_FEATURES[version] for version in target_versions)
 150
 151
 152 @dataclass
 153 class Mode:
 154     target_versions: Set[TargetVersion] = field(default_factory=set)
 155     line_length: int = DEFAULT_LINE_LENGTH
 156     string_normalization: bool = True
 157     is_pyi: bool = False
 158     is_ipynb: bool = False
 159     magic_trailing_comma: bool = True
 160     experimental_string_processing: bool = False
 161
 162     def get_cache_key(self) -> str:
 163         if self.target_versions:
 164             version_str = ",".join(
 165                 str(version.value)
 166                 for version in sorted(self.target_versions, key=attrgetter("value"))
 167             )
 168         else:
 169             version_str = "-"
 170         parts = [
 171             version_str,
 172             str(self.line_length),
 173             str(int(self.string_normalization)),
 174             str(int(self.is_pyi)),
 175             str(int(self.is_ipynb)),
 176             str(int(self.magic_trailing_comma)),
 177             str(int(self.experimental_string_processing)),
 178         ]
 179         return ".".join(parts)