Added explanatory comments.
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@ -1,14 +1,24 @@
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# module 'macpath'
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# module 'macpath' -- pathname (or -related) operations for the Macintosh
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import mac
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import string
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from stat import *
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# Return true if a path is absolute.
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# On the Mac, relative paths begin with a colon,
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# but as a special case, paths with no colons at all are also relative.
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# Anything else is absolute (the string up to the first colon is the
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# volume name).
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def isabs(s):
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return ':' in s and s[0] <> ':'
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# Concatenate two pathnames.
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# The result is equivalent to what the second pathname would refer to
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# if the first pathname were the current directory.
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def cat(s, t):
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if (not s) or isabs(t): return t
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if t[:1] = ':': t = t[1:]
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@ -18,9 +28,28 @@ def cat(s, t):
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s = s + ':'
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return s + t
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norm_error = 'path cannot be normalized'
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# Split a pathname in two parts: the directory leading up to the final bit,
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# and the basename (the filename, without colons, in that directory).
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# The result (s, t) is such that cat(s, t) yields the original argument.
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def split(s):
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if ':' not in s: return '', s
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colon = 0
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for i in range(len(s)):
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if s[i] = ':': colon = i+1
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return s[:colon], s[colon:]
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# Normalize a pathname: get rid of '::' sequences by backing up,
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# e.g., 'foo:bar::bletch' becomes 'foo:bletch'.
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# Raise the exception norm_error below if backing up is impossible,
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# e.g., for '::foo'.
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norm_error = 'macpath.norm_error: path cannot be normalized'
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def norm(s):
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import string
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if ':' not in s:
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return ':' + s
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f = string.splitfields(s, ':')
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@ -37,10 +66,10 @@ def norm(s):
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if seg:
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res.append(seg)
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else:
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if not res: raise norm_error # starts with '::'
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if not res: raise norm_error, 'path starts with ::'
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del res[len(res)-1]
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if not (pre or res):
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raise norm_error # starts with 'vol::'
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raise norm_error, 'path starts with volume::'
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if pre: res = pre + res
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if post: res = res + post
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s = res[0]
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@ -48,6 +77,9 @@ def norm(s):
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s = s + ':' + seg
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return s
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# Return true if the pathname refers to an existing directory.
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def isdir(s):
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try:
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st = mac.stat(s)
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@ -55,6 +87,9 @@ def isdir(s):
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return 0
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return S_ISDIR(st[ST_MODE])
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# Return true if the pathname refers to an existing regular file.
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def isfile(s):
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try:
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st = mac.stat(s)
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@ -62,6 +97,9 @@ def isfile(s):
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return 0
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return S_ISREG(st[ST_MODE])
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# Return true if the pathname refers to an existing file or directory.
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def exists(s):
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try:
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st = mac.stat(s)
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