| import codecs |
| import locale |
| import re |
| import sys |
| |
| from pip._internal.utils.typing import MYPY_CHECK_RUNNING |
| |
| if MYPY_CHECK_RUNNING: |
| from typing import List, Tuple, Text |
| |
| BOMS = [ |
| (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'), |
| ] # type: List[Tuple[bytes, Text]] |
| |
| ENCODING_RE = re.compile(br'coding[:=]\s*([-\w.]+)') |
| |
| |
| def auto_decode(data): |
| # type: (bytes) -> Text |
| """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): |
| encoding = ENCODING_RE.search(line).groups()[0].decode('ascii') |
| return data.decode(encoding) |
| return data.decode( |
| locale.getpreferredencoding(False) or sys.getdefaultencoding(), |
| ) |
