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     UNPACKING_ON_FLOW = 12
  53     FORCE_OPTIONAL_PARENTHESES = 50
  54
  55     # __future__ flags
  56     FUTURE_ANNOTATIONS = 51
  57
  58     # temporary for Python 2 deprecation
  59     PRINT_STMT = 200
  60     EXEC_STMT = 201
  61     AUTOMATIC_PARAMETER_UNPACKING = 202
  62     COMMA_STYLE_EXCEPT = 203
  63     COMMA_STYLE_RAISE = 204
  64     LONG_INT_LITERAL = 205
  65     OCTAL_INT_LITERAL = 206
  66     BACKQUOTE_REPR = 207
  67
  68
  69 FUTURE_FLAG_TO_FEATURE: Final = {
  70     "annotations": Feature.FUTURE_ANNOTATIONS,
  71 }
  72
  73
  74 VERSION_TO_FEATURES: Dict[TargetVersion, Set[Feature]] = {
  75     TargetVersion.PY27: {
  76         Feature.ASYNC_IDENTIFIERS,
  77         Feature.PRINT_STMT,
  78         Feature.EXEC_STMT,
  79         Feature.AUTOMATIC_PARAMETER_UNPACKING,
  80         Feature.COMMA_STYLE_EXCEPT,
  81         Feature.COMMA_STYLE_RAISE,
  82         Feature.LONG_INT_LITERAL,
  83         Feature.OCTAL_INT_LITERAL,
  84         Feature.BACKQUOTE_REPR,
  85     },
  86     TargetVersion.PY33: {Feature.UNICODE_LITERALS, Feature.ASYNC_IDENTIFIERS},
  87     TargetVersion.PY34: {Feature.UNICODE_LITERALS, Feature.ASYNC_IDENTIFIERS},
  88     TargetVersion.PY35: {
  89         Feature.UNICODE_LITERALS,
  90         Feature.TRAILING_COMMA_IN_CALL,
  91         Feature.ASYNC_IDENTIFIERS,
  92     },
  93     TargetVersion.PY36: {
  94         Feature.UNICODE_LITERALS,
  95         Feature.F_STRINGS,
  96         Feature.NUMERIC_UNDERSCORES,
  97         Feature.TRAILING_COMMA_IN_CALL,
  98         Feature.TRAILING_COMMA_IN_DEF,
  99         Feature.ASYNC_IDENTIFIERS,
 100     },
 101     TargetVersion.PY37: {
 102         Feature.UNICODE_LITERALS,
 103         Feature.F_STRINGS,
 104         Feature.NUMERIC_UNDERSCORES,
 105         Feature.TRAILING_COMMA_IN_CALL,
 106         Feature.TRAILING_COMMA_IN_DEF,
 107         Feature.ASYNC_KEYWORDS,
 108         Feature.FUTURE_ANNOTATIONS,
 109     },
 110     TargetVersion.PY38: {
 111         Feature.UNICODE_LITERALS,
 112         Feature.F_STRINGS,
 113         Feature.NUMERIC_UNDERSCORES,
 114         Feature.TRAILING_COMMA_IN_CALL,
 115         Feature.TRAILING_COMMA_IN_DEF,
 116         Feature.ASYNC_KEYWORDS,
 117         Feature.FUTURE_ANNOTATIONS,
 118         Feature.ASSIGNMENT_EXPRESSIONS,
 119         Feature.POS_ONLY_ARGUMENTS,
 120         Feature.UNPACKING_ON_FLOW,
 121     },
 122     TargetVersion.PY39: {
 123         Feature.UNICODE_LITERALS,
 124         Feature.F_STRINGS,
 125         Feature.NUMERIC_UNDERSCORES,
 126         Feature.TRAILING_COMMA_IN_CALL,
 127         Feature.TRAILING_COMMA_IN_DEF,
 128         Feature.ASYNC_KEYWORDS,
 129         Feature.FUTURE_ANNOTATIONS,
 130         Feature.ASSIGNMENT_EXPRESSIONS,
 131         Feature.RELAXED_DECORATORS,
 132         Feature.POS_ONLY_ARGUMENTS,
 133         Feature.UNPACKING_ON_FLOW,
 134     },
 135     TargetVersion.PY310: {
 136         Feature.UNICODE_LITERALS,
 137         Feature.F_STRINGS,
 138         Feature.NUMERIC_UNDERSCORES,
 139         Feature.TRAILING_COMMA_IN_CALL,
 140         Feature.TRAILING_COMMA_IN_DEF,
 141         Feature.ASYNC_KEYWORDS,
 142         Feature.FUTURE_ANNOTATIONS,
 143         Feature.ASSIGNMENT_EXPRESSIONS,
 144         Feature.RELAXED_DECORATORS,
 145         Feature.POS_ONLY_ARGUMENTS,
 146         Feature.UNPACKING_ON_FLOW,
 147         Feature.PATTERN_MATCHING,
 148     },
 149 }
 150
 151
 152 def supports_feature(target_versions: Set[TargetVersion], feature: Feature) -> bool:
 153     return all(feature in VERSION_TO_FEATURES[version] for version in target_versions)
 154
 155
 156 @dataclass
 157 class Mode:
 158     target_versions: Set[TargetVersion] = field(default_factory=set)
 159     line_length: int = DEFAULT_LINE_LENGTH
 160     string_normalization: bool = True
 161     is_pyi: bool = False
 162     is_ipynb: bool = False
 163     magic_trailing_comma: bool = True
 164     experimental_string_processing: bool = False
 165
 166     def get_cache_key(self) -> str:
 167         if self.target_versions:
 168             version_str = ",".join(
 169                 str(version.value)
 170                 for version in sorted(self.target_versions, key=attrgetter("value"))
 171             )
 172         else:
 173             version_str = "-"
 174         parts = [
 175             version_str,
 176             str(self.line_length),
 177             str(int(self.string_normalization)),
 178             str(int(self.is_pyi)),
 179             str(int(self.is_ipynb)),
 180             str(int(self.magic_trailing_comma)),
 181             str(int(self.experimental_string_processing)),
 182         ]
 183         return ".".join(parts)