Hope this answer helps shed some light on the mystery of file copying using core mechanisms in python. """copy data from file-like object fsrc to file-like object fdst""" (probably because the only way to check for hardlinks is to hashmap the os.lstat() ( st_ino and st_dev specifically) of the first inode we know about, and assume that's the hardlink target)Įlse, file copying is done via basic file buffers: with open(src, 'rb') as fsrc:Ĭopyfileobj() is a bit special in that it's buffer safe, using a length argument to read the file buffer in chunks: def copyfileobj(fsrc, fdst, length=16*1024): Hardlinks in posix are done with posix.link(), which pyfile() doesn't call, despite being callable through os.link(). If that test resolves True, the core code that copies a symlink/hardlink is: os.symlink(os.readlink(src), dst) (note that just because a module may be C doesn't inherently mean it's faster, know that what you use is actually written well before you use it)Īfter that initial testing, copyfile() runs a for loop on a dynamic tuple of (src, dst), testing for special files (such as sockets or devices in posix).įinally, if follow_symlinks is False, copyfile() tests if src is a symlink with os.path.islink(), which varies between nt.lstat() or posix.lstat() ( os.lstat()) on Windows and Linux, or (s, 0) on Mac. This part is mostly unneeded if you know for certain src and dst will never be the same file, otherwise a faster C approach could potentially be used. The way shutil works is symlink/hardlink safe, but is rather slow due to os.path.normpath() containing a while (nt, mac) or for (posix) loop, used in testing if src and dst are the same in pyfile() Recursively copy an entire directory tree rooted at src, returning the destination directory.įor the answer everyone recommends, if you prefer not to use the standard modules, or have completely removed them as I've done, preferring more core C methods over poorly written python methods py2() Copy with preserving the metadata In : py2(src, dst) In : os.stat(os.path.join(dst, 'Head+First+SQL.pdf')) py() Copy without preseving the metadata In : py(src, dst) # So dst should be a filename instead of a directory name IsADirectoryError: Is a directory: ~/desktop' pyfile(src, dst, *, follow_symlinks=True) Copy and rename In : pyfile(src, dst) In : os.stat(os.path.join(dst,'test.pdf')) In : with open(src, 'rb') as f1,open(os.path.join(dst,'test.pdf'), 'wb') as f2: pyfileobj(fsrc, fdst) manipulate opened objects In : src = '~/Documents/Head+First+SQL.pdf'ĪttributeError: 'str' object has no attribute 'read' Secondly, explaining methods of copy in examples: 'exception': ['exception shutil.SameFileError', Status = subprocess.check_output('copy source.txt destination.txt', shell=True)įirstly, I made an exhaustive cheat sheet of the shutil methods for your reference. Status = subprocess.check_output('cp source.txt destination.txt', shell=True) Subprocess.check_output signature subprocess.check_output(args, *, stdin=None, stderr=None, shell=False, universal_newlines=False) Status = subprocess.call('copy source.txt destination.txt', shell=True) Status = subprocess.call('cp source.txt destination.txt', shell=True) # example (WARNING: setting `shell=True` might be a security-risk) Subprocess.call signature subprocess.call(args, *, stdin=None, stdout=None, stderr=None, shell=False) ![]() Os.system('copy source.txt destination.txt') ![]() Os.system('cp source.txt destination.txt') Os.popen('copy source.txt destination.txt') Os.popen('cp source.txt destination.txt') pyfileobj signature pyfileobj(src_file_object, dest_file_object) ![]() py2 signature py2(src_file, dest_file, *, follow_symlinks=True) py signature py(src_file, dest_file, *, follow_symlinks=True) pyfile signature pyfile(src_file, dest_file, *, follow_symlinks=True)
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