boukeversteegh d21cd6e391 black
2020-07-01 13:15:03 +02:00

121 lines
3.0 KiB
Python

import re
# Word delimiters and symbols that will not be preserved when re-casing.
# language=PythonRegExp
SYMBOLS = "[^a-zA-Z0-9]*"
# Optionally capitalized word.
# language=PythonRegExp
WORD = "[A-Z]*[a-z]*[0-9]*"
# Uppercase word, not followed by lowercase letters.
# language=PythonRegExp
WORD_UPPER = "[A-Z]+(?![a-z])[0-9]*"
def safe_snake_case(value: str) -> str:
"""Snake case a value taking into account Python keywords."""
value = snake_case(value)
if value in [
"and",
"as",
"assert",
"break",
"class",
"continue",
"def",
"del",
"elif",
"else",
"except",
"finally",
"for",
"from",
"global",
"if",
"import",
"in",
"is",
"lambda",
"nonlocal",
"not",
"or",
"pass",
"raise",
"return",
"try",
"while",
"with",
"yield",
]:
# https://www.python.org/dev/peps/pep-0008/#descriptive-naming-styles
value += "_"
return value
def snake_case(value: str, strict: bool = True):
"""
Join words with an underscore into lowercase and remove symbols.
@param value: value to convert
@param strict: force single underscores
"""
def substitute_word(symbols, word, is_start):
if not word:
return ""
if strict:
delimiter_count = 0 if is_start else 1 # Single underscore if strict.
elif is_start:
delimiter_count = len(symbols)
elif word.isupper() or word.islower():
delimiter_count = max(
1, len(symbols)
) # Preserve all delimiters if not strict.
else:
delimiter_count = len(symbols) + 1 # Extra underscore for leading capital.
return ("_" * delimiter_count) + word.lower()
snake = re.sub(
f"(^)?({SYMBOLS})({WORD_UPPER}|{WORD})",
lambda groups: substitute_word(groups[2], groups[3], groups[1] is not None),
value,
)
return snake
def pascal_case(value: str, strict: bool = True):
"""
Capitalize each word and remove symbols.
@param value: value to convert
@param strict: output only alphanumeric characters
"""
def substitute_word(symbols, word):
if strict:
return word.capitalize() # Remove all delimiters
if word.islower():
delimiter_length = len(symbols[:-1]) # Lose one delimiter
else:
delimiter_length = len(symbols) # Preserve all delimiters
return ("_" * delimiter_length) + word.capitalize()
return re.sub(
f"({SYMBOLS})({WORD_UPPER}|{WORD})",
lambda groups: substitute_word(groups[1], groups[2]),
value,
)
def camel_case(value: str, strict: bool = True):
"""
Capitalize all words except first and remove symbols.
"""
return lowercase_first(pascal_case(value, strict=strict))
def lowercase_first(value: str):
return value[0:1].lower() + value[1:]