1 | # Module 'ntpath' -- common operations on WinNT/Win95 pathnames
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2 | """Common pathname manipulations, WindowsNT/95 version.
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3 |
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4 | Instead of importing this module directly, import os and refer to this
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5 | module as os.path.
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6 | """
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7 |
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8 | import os
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9 | import sys
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10 | import stat
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11 | import genericpath
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12 | import warnings
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13 |
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14 | from genericpath import *
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15 |
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16 | __all__ = ["normcase","isabs","join","splitdrive","split","splitext",
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17 | "basename","dirname","commonprefix","getsize","getmtime",
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18 | "getatime","getctime", "islink","exists","lexists","isdir","isfile",
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19 | "ismount","walk","expanduser","expandvars","normpath","abspath",
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20 | "splitunc","curdir","pardir","sep","pathsep","defpath","altsep",
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21 | "extsep","devnull","realpath","supports_unicode_filenames","relpath"]
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22 |
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23 | # strings representing various path-related bits and pieces
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24 | curdir = '.'
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25 | pardir = '..'
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26 | extsep = '.'
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27 | sep = '\\'
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28 | pathsep = ';'
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29 | altsep = '/'
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30 | defpath = '.;C:\\bin'
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31 | if 'ce' in sys.builtin_module_names:
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32 | defpath = '\\Windows'
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33 | elif 'os2' in sys.builtin_module_names:
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34 | # OS/2 w/ VACPP
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35 | altsep = '/'
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36 | devnull = 'nul'
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37 |
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38 | # Normalize the case of a pathname and map slashes to backslashes.
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39 | # Other normalizations (such as optimizing '../' away) are not done
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40 | # (this is done by normpath).
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41 |
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42 | def normcase(s):
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43 | """Normalize case of pathname.
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44 |
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45 | Makes all characters lowercase and all slashes into backslashes."""
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46 | return s.replace("/", "\\").lower()
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47 |
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48 |
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49 | # Return whether a path is absolute.
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50 | # Trivial in Posix, harder on the Mac or MS-DOS.
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51 | # For DOS it is absolute if it starts with a slash or backslash (current
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52 | # volume), or if a pathname after the volume letter and colon / UNC resource
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53 | # starts with a slash or backslash.
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54 |
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55 | def isabs(s):
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56 | """Test whether a path is absolute"""
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57 | s = splitdrive(s)[1]
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58 | return s != '' and s[:1] in '/\\'
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59 |
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60 |
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61 | # Join two (or more) paths.
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62 |
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63 | def join(a, *p):
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64 | """Join two or more pathname components, inserting "\\" as needed.
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65 | If any component is an absolute path, all previous path components
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66 | will be discarded."""
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67 | path = a
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68 | for b in p:
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69 | b_wins = 0 # set to 1 iff b makes path irrelevant
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70 | if path == "":
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71 | b_wins = 1
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72 |
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73 | elif isabs(b):
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74 | # This probably wipes out path so far. However, it's more
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75 | # complicated if path begins with a drive letter:
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76 | # 1. join('c:', '/a') == 'c:/a'
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77 | # 2. join('c:/', '/a') == 'c:/a'
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78 | # But
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79 | # 3. join('c:/a', '/b') == '/b'
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80 | # 4. join('c:', 'd:/') = 'd:/'
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81 | # 5. join('c:/', 'd:/') = 'd:/'
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82 | if path[1:2] != ":" or b[1:2] == ":":
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83 | # Path doesn't start with a drive letter, or cases 4 and 5.
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84 | b_wins = 1
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85 |
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86 | # Else path has a drive letter, and b doesn't but is absolute.
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87 | elif len(path) > 3 or (len(path) == 3 and
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88 | path[-1] not in "/\\"):
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89 | # case 3
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90 | b_wins = 1
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91 |
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92 | if b_wins:
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93 | path = b
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94 | else:
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95 | # Join, and ensure there's a separator.
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96 | assert len(path) > 0
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97 | if path[-1] in "/\\":
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98 | if b and b[0] in "/\\":
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99 | path += b[1:]
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100 | else:
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101 | path += b
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102 | elif path[-1] == ":":
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103 | path += b
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104 | elif b:
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105 | if b[0] in "/\\":
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106 | path += b
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107 | else:
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108 | path += "\\" + b
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109 | else:
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110 | # path is not empty and does not end with a backslash,
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111 | # but b is empty; since, e.g., split('a/') produces
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112 | # ('a', ''), it's best if join() adds a backslash in
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113 | # this case.
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114 | path += '\\'
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115 |
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116 | return path
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117 |
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118 |
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119 | # Split a path in a drive specification (a drive letter followed by a
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120 | # colon) and the path specification.
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121 | # It is always true that drivespec + pathspec == p
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122 | def splitdrive(p):
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123 | """Split a pathname into drive and path specifiers. Returns a 2-tuple
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124 | "(drive,path)"; either part may be empty"""
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125 | if p[1:2] == ':':
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126 | return p[0:2], p[2:]
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127 | return '', p
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128 |
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129 |
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130 | # Parse UNC paths
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131 | def splitunc(p):
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132 | """Split a pathname into UNC mount point and relative path specifiers.
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133 |
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134 | Return a 2-tuple (unc, rest); either part may be empty.
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135 | If unc is not empty, it has the form '//host/mount' (or similar
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136 | using backslashes). unc+rest is always the input path.
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137 | Paths containing drive letters never have an UNC part.
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138 | """
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139 | if p[1:2] == ':':
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140 | return '', p # Drive letter present
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141 | firstTwo = p[0:2]
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142 | if firstTwo == '//' or firstTwo == '\\\\':
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143 | # is a UNC path:
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144 | # vvvvvvvvvvvvvvvvvvvv equivalent to drive letter
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145 | # \\machine\mountpoint\directories...
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146 | # directory ^^^^^^^^^^^^^^^
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147 | normp = normcase(p)
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148 | index = normp.find('\\', 2)
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149 | if index == -1:
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150 | ##raise RuntimeError, 'illegal UNC path: "' + p + '"'
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151 | return ("", p)
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152 | index = normp.find('\\', index + 1)
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153 | if index == -1:
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154 | index = len(p)
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155 | return p[:index], p[index:]
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156 | return '', p
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157 |
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158 |
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159 | # Split a path in head (everything up to the last '/') and tail (the
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160 | # rest). After the trailing '/' is stripped, the invariant
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161 | # join(head, tail) == p holds.
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162 | # The resulting head won't end in '/' unless it is the root.
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163 |
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164 | def split(p):
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165 | """Split a pathname.
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166 |
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167 | Return tuple (head, tail) where tail is everything after the final slash.
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168 | Either part may be empty."""
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169 |
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170 | d, p = splitdrive(p)
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171 | # set i to index beyond p's last slash
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172 | i = len(p)
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173 | while i and p[i-1] not in '/\\':
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174 | i = i - 1
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175 | head, tail = p[:i], p[i:] # now tail has no slashes
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176 | # remove trailing slashes from head, unless it's all slashes
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177 | head2 = head
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178 | while head2 and head2[-1] in '/\\':
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179 | head2 = head2[:-1]
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180 | head = head2 or head
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181 | return d + head, tail
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182 |
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183 |
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184 | # Split a path in root and extension.
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185 | # The extension is everything starting at the last dot in the last
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186 | # pathname component; the root is everything before that.
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187 | # It is always true that root + ext == p.
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188 |
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189 | def splitext(p):
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190 | return genericpath._splitext(p, sep, altsep, extsep)
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191 | splitext.__doc__ = genericpath._splitext.__doc__
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192 |
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193 |
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194 | # Return the tail (basename) part of a path.
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195 |
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196 | def basename(p):
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197 | """Returns the final component of a pathname"""
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198 | return split(p)[1]
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199 |
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200 |
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201 | # Return the head (dirname) part of a path.
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202 |
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203 | def dirname(p):
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204 | """Returns the directory component of a pathname"""
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205 | return split(p)[0]
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206 |
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207 | # Is a path a symbolic link?
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208 | # This will always return false on systems where posix.lstat doesn't exist.
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209 |
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210 | def islink(path):
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211 | """Test for symbolic link.
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212 | On WindowsNT/95 and OS/2 always returns false
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213 | """
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214 | return False
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215 |
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216 | # alias exists to lexists
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217 | lexists = exists
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218 |
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219 | # Is a path a mount point? Either a root (with or without drive letter)
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220 | # or an UNC path with at most a / or \ after the mount point.
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221 |
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222 | def ismount(path):
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223 | """Test whether a path is a mount point (defined as root of drive)"""
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224 | unc, rest = splitunc(path)
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225 | if unc:
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226 | return rest in ("", "/", "\\")
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227 | p = splitdrive(path)[1]
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228 | return len(p) == 1 and p[0] in '/\\'
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229 |
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230 |
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231 | # Directory tree walk.
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232 | # For each directory under top (including top itself, but excluding
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233 | # '.' and '..'), func(arg, dirname, filenames) is called, where
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234 | # dirname is the name of the directory and filenames is the list
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235 | # of files (and subdirectories etc.) in the directory.
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236 | # The func may modify the filenames list, to implement a filter,
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237 | # or to impose a different order of visiting.
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238 |
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239 | def walk(top, func, arg):
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240 | """Directory tree walk with callback function.
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241 |
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242 | For each directory in the directory tree rooted at top (including top
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243 | itself, but excluding '.' and '..'), call func(arg, dirname, fnames).
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244 | dirname is the name of the directory, and fnames a list of the names of
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245 | the files and subdirectories in dirname (excluding '.' and '..'). func
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246 | may modify the fnames list in-place (e.g. via del or slice assignment),
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247 | and walk will only recurse into the subdirectories whose names remain in
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248 | fnames; this can be used to implement a filter, or to impose a specific
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249 | order of visiting. No semantics are defined for, or required of, arg,
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250 | beyond that arg is always passed to func. It can be used, e.g., to pass
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251 | a filename pattern, or a mutable object designed to accumulate
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252 | statistics. Passing None for arg is common."""
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253 | warnings.warnpy3k("In 3.x, os.path.walk is removed in favor of os.walk.",
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254 | stacklevel=2)
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255 | try:
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256 | names = os.listdir(top)
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257 | except os.error:
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258 | return
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259 | func(arg, top, names)
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260 | for name in names:
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261 | name = join(top, name)
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262 | if isdir(name):
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263 | walk(name, func, arg)
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264 |
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265 |
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266 | # Expand paths beginning with '~' or '~user'.
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267 | # '~' means $HOME; '~user' means that user's home directory.
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268 | # If the path doesn't begin with '~', or if the user or $HOME is unknown,
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269 | # the path is returned unchanged (leaving error reporting to whatever
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270 | # function is called with the expanded path as argument).
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271 | # See also module 'glob' for expansion of *, ? and [...] in pathnames.
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272 | # (A function should also be defined to do full *sh-style environment
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273 | # variable expansion.)
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274 |
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275 | def expanduser(path):
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276 | """Expand ~ and ~user constructs.
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277 |
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278 | If user or $HOME is unknown, do nothing."""
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279 | if path[:1] != '~':
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280 | return path
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281 | i, n = 1, len(path)
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282 | while i < n and path[i] not in '/\\':
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283 | i = i + 1
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284 |
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285 | if 'HOME' in os.environ:
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286 | userhome = os.environ['HOME']
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287 | elif 'USERPROFILE' in os.environ:
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288 | userhome = os.environ['USERPROFILE']
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289 | elif not 'HOMEPATH' in os.environ:
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290 | return path
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291 | else:
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292 | try:
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293 | drive = os.environ['HOMEDRIVE']
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294 | except KeyError:
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295 | drive = ''
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296 | userhome = join(drive, os.environ['HOMEPATH'])
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297 |
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298 | if i != 1: #~user
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299 | userhome = join(dirname(userhome), path[1:i])
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300 |
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301 | return userhome + path[i:]
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302 |
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303 |
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304 | # Expand paths containing shell variable substitutions.
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305 | # The following rules apply:
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306 | # - no expansion within single quotes
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307 | # - '$$' is translated into '$'
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308 | # - '%%' is translated into '%' if '%%' are not seen in %var1%%var2%
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309 | # - ${varname} is accepted.
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310 | # - $varname is accepted.
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311 | # - %varname% is accepted.
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312 | # - varnames can be made out of letters, digits and the characters '_-'
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313 | # (though is not verifed in the ${varname} and %varname% cases)
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314 | # XXX With COMMAND.COM you can use any characters in a variable name,
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315 | # XXX except '^|<>='.
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316 |
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317 | def expandvars(path):
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318 | """Expand shell variables of the forms $var, ${var} and %var%.
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319 |
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320 | Unknown variables are left unchanged."""
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321 | if '$' not in path and '%' not in path:
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322 | return path
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323 | import string
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324 | varchars = string.ascii_letters + string.digits + '_-'
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325 | res = ''
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326 | index = 0
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327 | pathlen = len(path)
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328 | while index < pathlen:
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329 | c = path[index]
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330 | if c == '\'': # no expansion within single quotes
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331 | path = path[index + 1:]
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332 | pathlen = len(path)
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333 | try:
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334 | index = path.index('\'')
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335 | res = res + '\'' + path[:index + 1]
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336 | except ValueError:
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337 | res = res + path
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338 | index = pathlen - 1
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339 | elif c == '%': # variable or '%'
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340 | if path[index + 1:index + 2] == '%':
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341 | res = res + c
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342 | index = index + 1
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343 | else:
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344 | path = path[index+1:]
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345 | pathlen = len(path)
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346 | try:
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347 | index = path.index('%')
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348 | except ValueError:
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349 | res = res + '%' + path
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350 | index = pathlen - 1
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351 | else:
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352 | var = path[:index]
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353 | if var in os.environ:
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354 | res = res + os.environ[var]
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355 | else:
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356 | res = res + '%' + var + '%'
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357 | elif c == '$': # variable or '$$'
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358 | if path[index + 1:index + 2] == '$':
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359 | res = res + c
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360 | index = index + 1
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361 | elif path[index + 1:index + 2] == '{':
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362 | path = path[index+2:]
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363 | pathlen = len(path)
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364 | try:
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365 | index = path.index('}')
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366 | var = path[:index]
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367 | if var in os.environ:
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368 | res = res + os.environ[var]
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369 | else:
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370 | res = res + '${' + var + '}'
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371 | except ValueError:
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372 | res = res + '${' + path
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373 | index = pathlen - 1
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374 | else:
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375 | var = ''
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376 | index = index + 1
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377 | c = path[index:index + 1]
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378 | while c != '' and c in varchars:
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379 | var = var + c
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380 | index = index + 1
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381 | c = path[index:index + 1]
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382 | if var in os.environ:
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383 | res = res + os.environ[var]
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384 | else:
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385 | res = res + '$' + var
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386 | if c != '':
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387 | index = index - 1
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388 | else:
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389 | res = res + c
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390 | index = index + 1
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391 | return res
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392 |
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393 |
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394 | # Normalize a path, e.g. A//B, A/./B and A/foo/../B all become A\B.
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395 | # Previously, this function also truncated pathnames to 8+3 format,
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396 | # but as this module is called "ntpath", that's obviously wrong!
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397 |
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398 | def normpath(path):
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399 | """Normalize path, eliminating double slashes, etc."""
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400 | # Preserve unicode (if path is unicode)
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401 | backslash, dot = (u'\\', u'.') if isinstance(path, unicode) else ('\\', '.')
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402 | path = path.replace("/", "\\")
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403 | prefix, path = splitdrive(path)
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404 | # We need to be careful here. If the prefix is empty, and the path starts
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405 | # with a backslash, it could either be an absolute path on the current
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406 | # drive (\dir1\dir2\file) or a UNC filename (\\server\mount\dir1\file). It
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407 | # is therefore imperative NOT to collapse multiple backslashes blindly in
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408 | # that case.
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409 | # The code below preserves multiple backslashes when there is no drive
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410 | # letter. This means that the invalid filename \\\a\b is preserved
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411 | # unchanged, where a\\\b is normalised to a\b. It's not clear that there
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412 | # is any better behaviour for such edge cases.
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413 | if prefix == '':
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414 | # No drive letter - preserve initial backslashes
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415 | while path[:1] == "\\":
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416 | prefix = prefix + backslash
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417 | path = path[1:]
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418 | else:
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419 | # We have a drive letter - collapse initial backslashes
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420 | if path.startswith("\\"):
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421 | prefix = prefix + backslash
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422 | path = path.lstrip("\\")
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423 | comps = path.split("\\")
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424 | i = 0
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425 | while i < len(comps):
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426 | if comps[i] in ('.', ''):
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427 | del comps[i]
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428 | elif comps[i] == '..':
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429 | if i > 0 and comps[i-1] != '..':
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430 | del comps[i-1:i+1]
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431 | i -= 1
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432 | elif i == 0 and prefix.endswith("\\"):
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433 | del comps[i]
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434 | else:
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435 | i += 1
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436 | else:
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437 | i += 1
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438 | # If the path is now empty, substitute '.'
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439 | if not prefix and not comps:
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440 | comps.append(dot)
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441 | return prefix + backslash.join(comps)
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442 |
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443 |
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444 | # Return an absolute path.
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445 | try:
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446 | from nt import _getfullpathname
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447 |
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448 | except ImportError: # not running on Windows - mock up something sensible
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449 | def abspath(path):
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450 | """Return the absolute version of a path."""
|
---|
451 | if not isabs(path):
|
---|
452 | if isinstance(path, unicode):
|
---|
453 | cwd = os.getcwdu()
|
---|
454 | else:
|
---|
455 | cwd = os.getcwd()
|
---|
456 | path = join(cwd, path)
|
---|
457 | return normpath(path)
|
---|
458 |
|
---|
459 | else: # use native Windows method on Windows
|
---|
460 | def abspath(path):
|
---|
461 | """Return the absolute version of a path."""
|
---|
462 |
|
---|
463 | if path: # Empty path must return current working directory.
|
---|
464 | try:
|
---|
465 | path = _getfullpathname(path)
|
---|
466 | except WindowsError:
|
---|
467 | pass # Bad path - return unchanged.
|
---|
468 | elif isinstance(path, unicode):
|
---|
469 | path = os.getcwdu()
|
---|
470 | else:
|
---|
471 | path = os.getcwd()
|
---|
472 | return normpath(path)
|
---|
473 |
|
---|
474 | # realpath is a no-op on systems without islink support
|
---|
475 | realpath = abspath
|
---|
476 | # Win9x family and earlier have no Unicode filename support.
|
---|
477 | supports_unicode_filenames = (hasattr(sys, "getwindowsversion") and
|
---|
478 | sys.getwindowsversion()[3] >= 2)
|
---|
479 |
|
---|
480 | def relpath(path, start=curdir):
|
---|
481 | """Return a relative version of a path"""
|
---|
482 |
|
---|
483 | if not path:
|
---|
484 | raise ValueError("no path specified")
|
---|
485 | start_list = abspath(start).split(sep)
|
---|
486 | path_list = abspath(path).split(sep)
|
---|
487 | if start_list[0].lower() != path_list[0].lower():
|
---|
488 | unc_path, rest = splitunc(path)
|
---|
489 | unc_start, rest = splitunc(start)
|
---|
490 | if bool(unc_path) ^ bool(unc_start):
|
---|
491 | raise ValueError("Cannot mix UNC and non-UNC paths (%s and %s)"
|
---|
492 | % (path, start))
|
---|
493 | else:
|
---|
494 | raise ValueError("path is on drive %s, start on drive %s"
|
---|
495 | % (path_list[0], start_list[0]))
|
---|
496 | # Work out how much of the filepath is shared by start and path.
|
---|
497 | for i in range(min(len(start_list), len(path_list))):
|
---|
498 | if start_list[i].lower() != path_list[i].lower():
|
---|
499 | break
|
---|
500 | else:
|
---|
501 | i += 1
|
---|
502 |
|
---|
503 | rel_list = [pardir] * (len(start_list)-i) + path_list[i:]
|
---|
504 | if not rel_list:
|
---|
505 | return curdir
|
---|
506 | return join(*rel_list)
|
---|