pre-commit-hooks/.venv/lib/python3.10/site-packages/pip/_internal/utils/encoding.py
2024-04-13 00:00:20 +00:00

39 lines
1.2 KiB
Python

from __future__ import annotations
import codecs
import locale
import re
import sys
from typing import List
from typing import Tuple
BOMS: list[tuple[bytes, str]] = [
(codecs.BOM_UTF8, 'utf-8'),
(codecs.BOM_UTF16, 'utf-16'),
(codecs.BOM_UTF16_BE, 'utf-16-be'),
(codecs.BOM_UTF16_LE, 'utf-16-le'),
(codecs.BOM_UTF32, 'utf-32'),
(codecs.BOM_UTF32_BE, 'utf-32-be'),
(codecs.BOM_UTF32_LE, 'utf-32-le'),
]
ENCODING_RE = re.compile(br'coding[:=]\s*([-\w.]+)')
def auto_decode(data: bytes) -> str:
"""Check a bytes string for a BOM to correctly detect the encoding
Fallback to locale.getpreferredencoding(False) like open() on Python3"""
for bom, encoding in BOMS:
if data.startswith(bom):
return data[len(bom):].decode(encoding)
# Lets check the first two lines as in PEP263
for line in data.split(b'\n')[:2]:
if line[0:1] == b'#' and ENCODING_RE.search(line):
result = ENCODING_RE.search(line)
assert result is not None
encoding = result.groups()[0].decode('ascii')
return data.decode(encoding)
return data.decode(
locale.getpreferredencoding(False) or sys.getdefaultencoding(),
)