| 1 | """
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| 2 | Path operations common to more than one OS
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| 3 | Do not use directly. The OS specific modules import the appropriate
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| 4 | functions from this module themselves.
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| 5 | """
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| 6 | import os
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| 7 | import stat
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| 8 |
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| 9 | __all__ = ['commonprefix', 'exists', 'getatime', 'getctime', 'getmtime',
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| 10 | 'getsize', 'isdir', 'isfile']
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| 11 |
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| 12 |
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| 13 | try:
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| 14 | _unicode = unicode
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| 15 | except NameError:
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| 16 | # If Python is built without Unicode support, the unicode type
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| 17 | # will not exist. Fake one.
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| 18 | class _unicode(object):
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| 19 | pass
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| 20 |
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| 21 | # Does a path exist?
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| 22 | # This is false for dangling symbolic links on systems that support them.
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| 23 | def exists(path):
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| 24 | """Test whether a path exists. Returns False for broken symbolic links"""
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| 25 | try:
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| 26 | os.stat(path)
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| 27 | except os.error:
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| 28 | return False
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| 29 | return True
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| 30 |
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| 31 |
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| 32 | # This follows symbolic links, so both islink() and isdir() can be true
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| 33 | # for the same path on systems that support symlinks
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| 34 | def isfile(path):
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| 35 | """Test whether a path is a regular file"""
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| 36 | try:
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| 37 | st = os.stat(path)
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| 38 | except os.error:
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| 39 | return False
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| 40 | return stat.S_ISREG(st.st_mode)
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| 41 |
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| 42 |
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| 43 | # Is a path a directory?
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| 44 | # This follows symbolic links, so both islink() and isdir()
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| 45 | # can be true for the same path on systems that support symlinks
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| 46 | def isdir(s):
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| 47 | """Return true if the pathname refers to an existing directory."""
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| 48 | try:
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| 49 | st = os.stat(s)
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| 50 | except os.error:
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| 51 | return False
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| 52 | return stat.S_ISDIR(st.st_mode)
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| 53 |
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| 54 |
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| 55 | def getsize(filename):
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| 56 | """Return the size of a file, reported by os.stat()."""
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| 57 | return os.stat(filename).st_size
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| 58 |
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| 59 |
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| 60 | def getmtime(filename):
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| 61 | """Return the last modification time of a file, reported by os.stat()."""
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| 62 | return os.stat(filename).st_mtime
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| 63 |
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| 64 |
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| 65 | def getatime(filename):
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| 66 | """Return the last access time of a file, reported by os.stat()."""
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| 67 | return os.stat(filename).st_atime
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| 68 |
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| 69 |
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| 70 | def getctime(filename):
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| 71 | """Return the metadata change time of a file, reported by os.stat()."""
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| 72 | return os.stat(filename).st_ctime
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| 73 |
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| 74 |
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| 75 | # Return the longest prefix of all list elements.
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| 76 | def commonprefix(m):
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| 77 | "Given a list of pathnames, returns the longest common leading component"
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| 78 | if not m: return ''
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| 79 | s1 = min(m)
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| 80 | s2 = max(m)
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| 81 | for i, c in enumerate(s1):
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| 82 | if c != s2[i]:
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| 83 | return s1[:i]
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| 84 | return s1
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| 85 |
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| 86 | # Split a path in root and extension.
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| 87 | # The extension is everything starting at the last dot in the last
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| 88 | # pathname component; the root is everything before that.
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| 89 | # It is always true that root + ext == p.
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| 90 |
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| 91 | # Generic implementation of splitext, to be parametrized with
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| 92 | # the separators
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| 93 | def _splitext(p, sep, altsep, extsep):
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| 94 | """Split the extension from a pathname.
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| 95 |
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| 96 | Extension is everything from the last dot to the end, ignoring
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| 97 | leading dots. Returns "(root, ext)"; ext may be empty."""
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| 98 |
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| 99 | sepIndex = p.rfind(sep)
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| 100 | if altsep:
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| 101 | altsepIndex = p.rfind(altsep)
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| 102 | sepIndex = max(sepIndex, altsepIndex)
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| 103 |
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| 104 | dotIndex = p.rfind(extsep)
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| 105 | if dotIndex > sepIndex:
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| 106 | # skip all leading dots
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| 107 | filenameIndex = sepIndex + 1
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| 108 | while filenameIndex < dotIndex:
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| 109 | if p[filenameIndex] != extsep:
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| 110 | return p[:dotIndex], p[dotIndex:]
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| 111 | filenameIndex += 1
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| 112 |
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| 113 | return p, ''
|