-# Module 'ntpath' -- common operations on DOS pathnames
+# Module 'ntpath' -- common operations on WinNT/Win95 pathnames
+"""Common pathname manipulations, WindowsNT/95 version.
+Instead of importing this module
+directly, import os and refer to this module as os.path.
+"""
import os
import stat
# (this is done by normpath).
_normtable = string.maketrans(string.uppercase + "\\/",
- string.lowercase + os.sep * 2)
+ string.lowercase + os.sep * 2)
def normcase(s):
+ """Normalize case of pathname. Makes all characters lowercase and all
+slashes into backslashes"""
return string.translate(s, _normtable)
# a slash or backslash.
def isabs(s):
- s = splitdrive(s)[1]
- return s != '' and s[:1] in '/\\'
+ """Test whether a path is absolute"""
+ s = splitdrive(s)[1]
+ return s != '' and s[:1] in '/\\'
# Join two (or more) paths.
def join(a, *p):
- path = a
- for b in p:
- if isabs(b):
- path = b
- elif path == '' or path[-1:] in '/\\':
- path = path + b
- else:
- path = path + os.sep + b
- return path
+ """Join two or more pathname components, inserting "\\" as needed"""
+ path = a
+ for b in p:
+ if isabs(b):
+ path = b
+ elif path == '' or path[-1:] in '/\\':
+ path = path + b
+ else:
+ path = path + os.sep + b
+ return path
# Split a path in a drive specification (a drive letter followed by a
# colon) and the path specification.
# It is always true that drivespec + pathspec == p
def splitdrive(p):
- if p[1:2] == ':':
- return p[0:2], p[2:]
- return '', p
+ """Split a pathname into drive and path specifiers. Returns a 2-tuple
+"(drive,path)"; either part may be empty"""
+ if p[1:2] == ':':
+ return p[0:2], p[2:]
+ return '', p
# Split a path in head (everything up to the last '/') and tail (the
# The resulting head won't end in '/' unless it is the root.
def split(p):
- d, p = splitdrive(p)
- slashes = ''
- while p and p[-1:] in '/\\':
- slashes = slashes + p[-1]
- p = p[:-1]
- if p == '':
- p = p + slashes
- head, tail = '', ''
- for c in p:
- tail = tail + c
- if c in '/\\':
- head, tail = head + tail, ''
- slashes = ''
- while head and head[-1:] in '/\\':
- slashes = slashes + head[-1]
- head = head[:-1]
- if head == '':
- head = head + slashes
- return d + head, tail
+ """Split a pathname. Returns tuple "(head, tail)" where "tail" is
+everything after the final slash. Either part may be empty"""
+ d, p = splitdrive(p)
+ slashes = ''
+ while p and p[-1:] in '/\\':
+ slashes = slashes + p[-1]
+ p = p[:-1]
+ if p == '':
+ p = p + slashes
+ head, tail = '', ''
+ for c in p:
+ tail = tail + c
+ if c in '/\\':
+ head, tail = head + tail, ''
+ slashes = ''
+ while head and head[-1:] in '/\\':
+ slashes = slashes + head[-1]
+ head = head[:-1]
+ if head == '':
+ head = head + slashes
+ return d + head, tail
# Split a path in root and extension.
# It is always true that root + ext == p.
def splitext(p):
- root, ext = '', ''
- for c in p:
- if c in ['/','\\']:
- root, ext = root + ext + c, ''
- elif c == '.':
- if ext:
- root, ext = root + ext, c
- else:
- ext = c
- elif ext:
- ext = ext + c
- else:
- root = root + c
- return root, ext
+ """Split the extension from a pathname. Extension is everything from the
+last dot to the end. Returns "(root, ext)", either part may be empty"""
+ root, ext = '', ''
+ for c in p:
+ if c in ['/','\\']:
+ root, ext = root + ext + c, ''
+ elif c == '.':
+ if ext:
+ root, ext = root + ext, c
+ else:
+ ext = c
+ elif ext:
+ ext = ext + c
+ else:
+ root = root + c
+ return root, ext
# Return the tail (basename) part of a path.
def basename(p):
- return split(p)[1]
+ """Returns the final component of a pathname"""
+ return split(p)[1]
# Return the head (dirname) part of a path.
def dirname(p):
- return split(p)[0]
+ """Returns the directory component of a pathname"""
+ return split(p)[0]
# Return the longest prefix of all list elements.
def commonprefix(m):
- if not m: return ''
- prefix = m[0]
- for item in m:
- for i in range(len(prefix)):
- if prefix[:i+1] <> item[:i+1]:
- prefix = prefix[:i]
- if i == 0: return ''
- break
- return prefix
+ "Given a list of pathnames, returns the longest common leading component"
+ if not m: return ''
+ prefix = m[0]
+ for item in m:
+ for i in range(len(prefix)):
+ if prefix[:i+1] <> item[:i+1]:
+ prefix = prefix[:i]
+ if i == 0: return ''
+ break
+ return prefix
# Is a path a symbolic link?
# This will always return false on systems where posix.lstat doesn't exist.
def islink(path):
- return 0
+ """Test for symbolic link. On WindowsNT/95 always returns false"""
+ return 0
# Does a path exist?
# This is false for dangling symbolic links.
def exists(path):
- try:
- st = os.stat(path)
- except os.error:
- return 0
- return 1
+ """Test whether a path exists"""
+ try:
+ st = os.stat(path)
+ except os.error:
+ return 0
+ return 1
# Is a path a dos directory?
# for the same path.
def isdir(path):
- try:
- st = os.stat(path)
- except os.error:
- return 0
- return stat.S_ISDIR(st[stat.ST_MODE])
+ """Test whether a path is a directory"""
+ try:
+ st = os.stat(path)
+ except os.error:
+ return 0
+ return stat.S_ISDIR(st[stat.ST_MODE])
# Is a path a regular file?
# for the same path.
def isfile(path):
- try:
- st = os.stat(path)
- except os.error:
- return 0
- return stat.S_ISREG(st[stat.ST_MODE])
+ """Test whether a path is a regular file"""
+ try:
+ st = os.stat(path)
+ except os.error:
+ return 0
+ return stat.S_ISREG(st[stat.ST_MODE])
# Are two filenames really pointing to the same file?
def samefile(f1, f2):
- s1 = os.stat(f1)
- s2 = os.stat(f2)
- return samestat(s1, s2)
+ """Test whether two pathnames reference the same actual file"""
+ s1 = os.stat(f1)
+ s2 = os.stat(f2)
+ return samestat(s1, s2)
# Are two open files really referencing the same file?
# XXX THIS IS BROKEN UNDER DOS! ST_INO seems to indicate number of reads?
def sameopenfile(fp1, fp2):
- s1 = os.fstat(fp1.fileno())
- s2 = os.fstat(fp2.fileno())
- return samestat(s1, s2)
+ """Test whether two open file objects reference the same file (may not
+work correctly)"""
+ s1 = os.fstat(fp1.fileno())
+ s2 = os.fstat(fp2.fileno())
+ return samestat(s1, s2)
# Are two stat buffers (obtained from stat, fstat or lstat)
# describing the same file?
def samestat(s1, s2):
- return s1[stat.ST_INO] == s2[stat.ST_INO] and \
- s1[stat.ST_DEV] == s2[stat.ST_DEV]
+ """Test whether two stat buffers reference the same file"""
+ return s1[stat.ST_INO] == s2[stat.ST_INO] and \
+ s1[stat.ST_DEV] == s2[stat.ST_DEV]
# Is a path a mount point?
# XXX This degenerates in: 'is this the root?' on DOS
def ismount(path):
- return isabs(splitdrive(path)[1])
+ """Test whether a path is a mount point"""
+ return isabs(splitdrive(path)[1])
# Directory tree walk.
# or to impose a different order of visiting.
def walk(top, func, arg):
- try:
- names = os.listdir(top)
- except os.error:
- return
- func(arg, top, names)
- exceptions = ('.', '..')
- for name in names:
- if name not in exceptions:
- name = join(top, name)
- if isdir(name):
- walk(name, func, arg)
+ """walk(top,func,args) calls func(arg, d, files) for each directory "d"
+in the tree rooted at "top" (including "top" itself). "files" is a list
+of all the files and subdirs in directory "d".
+"""
+ try:
+ names = os.listdir(top)
+ except os.error:
+ return
+ func(arg, top, names)
+ exceptions = ('.', '..')
+ for name in names:
+ if name not in exceptions:
+ name = join(top, name)
+ if isdir(name):
+ walk(name, func, arg)
# Expand paths beginning with '~' or '~user'.
# variable expansion.)
def expanduser(path):
- if path[:1] <> '~':
- return path
- i, n = 1, len(path)
- while i < n and path[i] not in '/\\':
- i = i+1
- if i == 1:
- if os.environ.has_key('HOME'):
- userhome = os.environ['HOME']
- elif not os.environ.has_key('HOMEPATH'):
- return path
- else:
- try:
- drive=os.environ['HOMEDRIVE']
- except KeyError:
- drive = ''
- userhome = join(drive, os.environ['HOMEPATH'])
- else:
- return path
- return userhome + path[i:]
+ """Expand ~ and ~user constructions. If user or $HOME is unknown,
+do nothing"""
+ if path[:1] <> '~':
+ return path
+ i, n = 1, len(path)
+ while i < n and path[i] not in '/\\':
+ i = i+1
+ if i == 1:
+ if os.environ.has_key('HOME'):
+ userhome = os.environ['HOME']
+ elif not os.environ.has_key('HOMEPATH'):
+ return path
+ else:
+ try:
+ drive=os.environ['HOMEDRIVE']
+ except KeyError:
+ drive = ''
+ userhome = join(drive, os.environ['HOMEPATH'])
+ else:
+ return path
+ return userhome + path[i:]
# Expand paths containing shell variable substitutions.
# The following rules apply:
-# - no expansion within single quotes
-# - no escape character, except for '$$' which is translated into '$'
-# - ${varname} is accepted.
-# - varnames can be made out of letters, digits and the character '_'
+# - no expansion within single quotes
+# - no escape character, except for '$$' which is translated into '$'
+# - ${varname} is accepted.
+# - varnames can be made out of letters, digits and the character '_'
# XXX With COMMAND.COM you can use any characters in a variable name,
# XXX except '^|<>='.
varchars = string.letters + string.digits + '_-'
-def expandvars(path):
- if '$' not in path:
- return path
- res = ''
- index = 0
- pathlen = len(path)
- while index < pathlen:
- c = path[index]
- if c == '\'': # no expansion within single quotes
- path = path[index + 1:]
- pathlen = len(path)
- try:
- index = string.index(path, '\'')
- res = res + '\'' + path[:index + 1]
- except string.index_error:
- res = res + path
- index = pathlen -1
- elif c == '$': # variable or '$$'
- if path[index + 1:index + 2] == '$':
- res = res + c
- index = index + 1
- elif path[index + 1:index + 2] == '{':
- path = path[index+2:]
- pathlen = len(path)
- try:
- index = string.index(path, '}')
- var = path[:index]
- if os.environ.has_key(var):
- res = res + os.environ[var]
- except string.index_error:
- res = res + path
- index = pathlen - 1
- else:
- var = ''
- index = index + 1
- c = path[index:index + 1]
- while c != '' and c in varchars:
- var = var + c
- index = index + 1
- c = path[index:index + 1]
- if os.environ.has_key(var):
- res = res + os.environ[var]
- if c != '':
- res = res + c
- else:
- res = res + c
- index = index + 1
- return res
+def expandvars(path):
+ """Expand shell variables of form $var and ${var}. Unknown variables
+are left unchanged"""
+ if '$' not in path:
+ return path
+ res = ''
+ index = 0
+ pathlen = len(path)
+ while index < pathlen:
+ c = path[index]
+ if c == '\'': # no expansion within single quotes
+ path = path[index + 1:]
+ pathlen = len(path)
+ try:
+ index = string.index(path, '\'')
+ res = res + '\'' + path[:index + 1]
+ except string.index_error:
+ res = res + path
+ index = pathlen -1
+ elif c == '$': # variable or '$$'
+ if path[index + 1:index + 2] == '$':
+ res = res + c
+ index = index + 1
+ elif path[index + 1:index + 2] == '{':
+ path = path[index+2:]
+ pathlen = len(path)
+ try:
+ index = string.index(path, '}')
+ var = path[:index]
+ if os.environ.has_key(var):
+ res = res + os.environ[var]
+ except string.index_error:
+ res = res + path
+ index = pathlen - 1
+ else:
+ var = ''
+ index = index + 1
+ c = path[index:index + 1]
+ while c != '' and c in varchars:
+ var = var + c
+ index = index + 1
+ c = path[index:index + 1]
+ if os.environ.has_key(var):
+ res = res + os.environ[var]
+ if c != '':
+ res = res + c
+ else:
+ res = res + c
+ index = index + 1
+ return res
# Normalize a path, e.g. A//B, A/./B and A/foo/../B all become A/B.
# but as this module is called "ntpath", that's obviously wrong!
def normpath(path):
- path = normcase(path)
- prefix, path = splitdrive(path)
- while path[:1] == os.sep:
- prefix = prefix + os.sep
- path = path[1:]
- comps = string.splitfields(path, os.sep)
- i = 0
- while i < len(comps):
- if comps[i] == '.':
- del comps[i]
- elif comps[i] == '..' and i > 0 and \
- comps[i-1] not in ('', '..'):
- del comps[i-1:i+1]
- i = i-1
- elif comps[i] == '' and i > 0 and comps[i-1] <> '':
- del comps[i]
- else:
- i = i+1
- # If the path is now empty, substitute '.'
- if not prefix and not comps:
- comps.append('.')
- return prefix + string.joinfields(comps, os.sep)
+ """Normalize path, eliminating double slashes, etc."""
+ path = normcase(path)
+ prefix, path = splitdrive(path)
+ while path[:1] == os.sep:
+ prefix = prefix + os.sep
+ path = path[1:]
+ comps = string.splitfields(path, os.sep)
+ i = 0
+ while i < len(comps):
+ if comps[i] == '.':
+ del comps[i]
+ elif comps[i] == '..' and i > 0 and comps[i-1] not in ('', '..'):
+ del comps[i-1:i+1]
+ i = i-1
+ elif comps[i] == '' and i > 0 and comps[i-1] <> '':
+ del comps[i]
+ else:
+ i = i+1
+ # If the path is now empty, substitute '.'
+ if not prefix and not comps:
+ comps.append('.')
+ return prefix + string.joinfields(comps, os.sep)
projects / python / commitdiff