cpython/Tools/freeze/bkfile.py

27 lines
664 B
Python

from builtins import open as _orig_open
def open(file, mode='r', bufsize=-1):
if 'w' not in mode:
return _orig_open(file, mode, bufsize)
import os
backup = file + '~'
try:
os.unlink(backup)
except OSError:
pass
try:
os.rename(file, backup)
except OSError:
return _orig_open(file, mode, bufsize)
f = _orig_open(file, mode, bufsize)
_orig_close = f.close
def close():
_orig_close()
import filecmp
if filecmp.cmp(backup, file, shallow=False):
import os
os.unlink(file)
os.rename(backup, file)
f.close = close
return f