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     PY33 = 3
  24     PY34 = 4
  25     PY35 = 5
  26     PY36 = 6
  27     PY37 = 7
  28     PY38 = 8
  29     PY39 = 9
  30     PY310 = 10
  31
  32
  33 class Feature(Enum):
  34     F_STRINGS = 2
  35     NUMERIC_UNDERSCORES = 3
  36     TRAILING_COMMA_IN_CALL = 4
  37     TRAILING_COMMA_IN_DEF = 5
  38     # The following two feature-flags are mutually exclusive, and exactly one should be
  39     # set for every version of python.
  40     ASYNC_IDENTIFIERS = 6
  41     ASYNC_KEYWORDS = 7
  42     ASSIGNMENT_EXPRESSIONS = 8
  43     POS_ONLY_ARGUMENTS = 9
  44     RELAXED_DECORATORS = 10
  45     PATTERN_MATCHING = 11
  46     UNPACKING_ON_FLOW = 12
  47     ANN_ASSIGN_EXTENDED_RHS = 13
  48     FORCE_OPTIONAL_PARENTHESES = 50
  49
  50     # __future__ flags
  51     FUTURE_ANNOTATIONS = 51
  52
  53
  54 FUTURE_FLAG_TO_FEATURE: Final = {
  55     "annotations": Feature.FUTURE_ANNOTATIONS,
  56 }
  57
  58
  59 VERSION_TO_FEATURES: Dict[TargetVersion, Set[Feature]] = {
  60     TargetVersion.PY33: {Feature.ASYNC_IDENTIFIERS},
  61     TargetVersion.PY34: {Feature.ASYNC_IDENTIFIERS},
  62     TargetVersion.PY35: {Feature.TRAILING_COMMA_IN_CALL, Feature.ASYNC_IDENTIFIERS},
  63     TargetVersion.PY36: {
  64         Feature.F_STRINGS,
  65         Feature.NUMERIC_UNDERSCORES,
  66         Feature.TRAILING_COMMA_IN_CALL,
  67         Feature.TRAILING_COMMA_IN_DEF,
  68         Feature.ASYNC_IDENTIFIERS,
  69     },
  70     TargetVersion.PY37: {
  71         Feature.F_STRINGS,
  72         Feature.NUMERIC_UNDERSCORES,
  73         Feature.TRAILING_COMMA_IN_CALL,
  74         Feature.TRAILING_COMMA_IN_DEF,
  75         Feature.ASYNC_KEYWORDS,
  76         Feature.FUTURE_ANNOTATIONS,
  77     },
  78     TargetVersion.PY38: {
  79         Feature.F_STRINGS,
  80         Feature.NUMERIC_UNDERSCORES,
  81         Feature.TRAILING_COMMA_IN_CALL,
  82         Feature.TRAILING_COMMA_IN_DEF,
  83         Feature.ASYNC_KEYWORDS,
  84         Feature.FUTURE_ANNOTATIONS,
  85         Feature.ASSIGNMENT_EXPRESSIONS,
  86         Feature.POS_ONLY_ARGUMENTS,
  87         Feature.UNPACKING_ON_FLOW,
  88         Feature.ANN_ASSIGN_EXTENDED_RHS,
  89     },
  90     TargetVersion.PY39: {
  91         Feature.F_STRINGS,
  92         Feature.NUMERIC_UNDERSCORES,
  93         Feature.TRAILING_COMMA_IN_CALL,
  94         Feature.TRAILING_COMMA_IN_DEF,
  95         Feature.ASYNC_KEYWORDS,
  96         Feature.FUTURE_ANNOTATIONS,
  97         Feature.ASSIGNMENT_EXPRESSIONS,
  98         Feature.RELAXED_DECORATORS,
  99         Feature.POS_ONLY_ARGUMENTS,
 100         Feature.UNPACKING_ON_FLOW,
 101         Feature.ANN_ASSIGN_EXTENDED_RHS,
 102     },
 103     TargetVersion.PY310: {
 104         Feature.F_STRINGS,
 105         Feature.NUMERIC_UNDERSCORES,
 106         Feature.TRAILING_COMMA_IN_CALL,
 107         Feature.TRAILING_COMMA_IN_DEF,
 108         Feature.ASYNC_KEYWORDS,
 109         Feature.FUTURE_ANNOTATIONS,
 110         Feature.ASSIGNMENT_EXPRESSIONS,
 111         Feature.RELAXED_DECORATORS,
 112         Feature.POS_ONLY_ARGUMENTS,
 113         Feature.UNPACKING_ON_FLOW,
 114         Feature.ANN_ASSIGN_EXTENDED_RHS,
 115         Feature.PATTERN_MATCHING,
 116     },
 117 }
 118
 119
 120 def supports_feature(target_versions: Set[TargetVersion], feature: Feature) -> bool:
 121     return all(feature in VERSION_TO_FEATURES[version] for version in target_versions)
 122
 123
 124 @dataclass
 125 class Mode:
 126     target_versions: Set[TargetVersion] = field(default_factory=set)
 127     line_length: int = DEFAULT_LINE_LENGTH
 128     string_normalization: bool = True
 129     is_pyi: bool = False
 130     is_ipynb: bool = False
 131     magic_trailing_comma: bool = True
 132     experimental_string_processing: bool = False
 133
 134     def get_cache_key(self) -> str:
 135         if self.target_versions:
 136             version_str = ",".join(
 137                 str(version.value)
 138                 for version in sorted(self.target_versions, key=attrgetter("value"))
 139             )
 140         else:
 141             version_str = "-"
 142         parts = [
 143             version_str,
 144             str(self.line_length),
 145             str(int(self.string_normalization)),
 146             str(int(self.is_pyi)),
 147             str(int(self.is_ipynb)),
 148             str(int(self.magic_trailing_comma)),
 149             str(int(self.experimental_string_processing)),
 150         ]
 151         return ".".join(parts)