137 lines
5.1 KiB
TeX
137 lines
5.1 KiB
TeX
\section{Standard Module \sectcode{posixpath}}
|
|
\label{module-posixpath}
|
|
\stmodindex{posixpath}
|
|
|
|
This module implements some useful functions on POSIX pathnames.
|
|
|
|
\strong{Do not import this module directly.} Instead, import the
|
|
module \code{os} and use \code{os.path}.
|
|
\refstmodindex{os}
|
|
|
|
\renewcommand{\indexsubitem}{(in module posixpath)}
|
|
|
|
\begin{funcdesc}{basename}{p}
|
|
Return the base name of pathname
|
|
\var{p}.
|
|
This is the second half of the pair returned by
|
|
\code{posixpath.split(\var{p})}.
|
|
\end{funcdesc}
|
|
|
|
\begin{funcdesc}{commonprefix}{list}
|
|
Return the longest string that is a prefix of all strings in
|
|
\var{list}.
|
|
If
|
|
\var{list}
|
|
is empty, return the empty string (\code{''}).
|
|
\end{funcdesc}
|
|
|
|
\begin{funcdesc}{exists}{p}
|
|
Return true if
|
|
\var{p}
|
|
refers to an existing path.
|
|
\end{funcdesc}
|
|
|
|
\begin{funcdesc}{expanduser}{p}
|
|
Return the argument with an initial component of \samp{\~} or
|
|
\samp{\~\var{user}} replaced by that \var{user}'s home directory. An
|
|
initial \samp{\~{}} is replaced by the environment variable \code{\${}HOME};
|
|
an initial \samp{\~\var{user}} is looked up in the password directory through
|
|
the built-in module \code{pwd}. If the expansion fails, or if the
|
|
path does not begin with a tilde, the path is returned unchanged.
|
|
\refbimodindex{pwd}
|
|
\end{funcdesc}
|
|
|
|
\begin{funcdesc}{expandvars}{p}
|
|
Return the argument with environment variables expanded. Substrings
|
|
of the form \samp{\$\var{name}} or \samp{\$\{\var{name}\}} are
|
|
replaced by the value of environment variable \var{name}. Malformed
|
|
variable names and references to non-existing variables are left
|
|
unchanged.
|
|
\end{funcdesc}
|
|
|
|
\begin{funcdesc}{isabs}{p}
|
|
Return true if \var{p} is an absolute pathname (begins with a slash).
|
|
\end{funcdesc}
|
|
|
|
\begin{funcdesc}{isfile}{p}
|
|
Return true if \var{p} is an existing regular file. This follows
|
|
symbolic links, so both \code{islink()} and \code{isfile()} can be
|
|
true for the same path.
|
|
\end{funcdesc}
|
|
|
|
\begin{funcdesc}{isdir}{p}
|
|
Return true if \var{p} is an existing directory. This follows
|
|
symbolic links, so both \code{islink()} and \code{isdir()} can be true
|
|
for the same path.
|
|
\end{funcdesc}
|
|
|
|
\begin{funcdesc}{islink}{p}
|
|
Return true if
|
|
\var{p}
|
|
refers to a directory entry that is a symbolic link.
|
|
Always false if symbolic links are not supported.
|
|
\end{funcdesc}
|
|
|
|
\begin{funcdesc}{ismount}{p}
|
|
Return true if pathname \var{p} is a \dfn{mount point}: a point in a
|
|
file system where a different file system has been mounted. The
|
|
function checks whether \var{p}'s parent, \file{\var{p}/..}, is on a
|
|
different device than \var{p}, or whether \file{\var{p}/..} and
|
|
\var{p} point to the same i-node on the same device --- this should
|
|
detect mount points for all \UNIX{} and POSIX variants.
|
|
\end{funcdesc}
|
|
|
|
\begin{funcdesc}{join}{p\optional{\, q\optional{\, ...}}}
|
|
Joins one or more path components intelligently. If any component is
|
|
an absolute path, all previous components are thrown away, and joining
|
|
continues. The return value is the concatenation of \var{p}, and
|
|
optionally \var{q}, etc., with exactly one slash (\code{'/'}) inserted
|
|
between components, unless \var{p} is empty.
|
|
\end{funcdesc}
|
|
|
|
\begin{funcdesc}{normcase}{p}
|
|
Normalize the case of a pathname. This returns the path unchanged;
|
|
however, a similar function in \code{macpath} converts upper case to
|
|
lower case.
|
|
\end{funcdesc}
|
|
|
|
\begin{funcdesc}{samefile}{p\, q}
|
|
Return true if both pathname arguments refer to the same file or directory
|
|
(as indicated by device number and i-node number).
|
|
Raise an exception if a \code{stat()} call on either pathname fails.
|
|
\end{funcdesc}
|
|
|
|
\begin{funcdesc}{split}{p}
|
|
Split the pathname \var{p} in a pair \code{(\var{head}, \var{tail})},
|
|
where \var{tail} is the last pathname component and \var{head} is
|
|
everything leading up to that. The \var{tail} part will never contain
|
|
a slash; if \var{p} ends in a slash, \var{tail} will be empty. If
|
|
there is no slash in \var{p}, \var{head} will be empty. If \var{p} is
|
|
empty, both \var{head} and \var{tail} are empty. Trailing slashes are
|
|
stripped from \var{head} unless it is the root (one or more slashes
|
|
only). In nearly all cases, \code{join(\var{head}, \var{tail})}
|
|
equals \var{p} (the only exception being when there were multiple
|
|
slashes separating \var{head} from \var{tail}).
|
|
\end{funcdesc}
|
|
|
|
\begin{funcdesc}{splitext}{p}
|
|
Split the pathname \var{p} in a pair \code{(\var{root}, \var{ext})}
|
|
such that \code{\var{root} + \var{ext} == \var{p}},
|
|
and \var{ext} is empty or begins with a period and contains
|
|
at most one period.
|
|
\end{funcdesc}
|
|
|
|
\begin{funcdesc}{walk}{p\, visit\, arg}
|
|
Calls the function \var{visit} with arguments
|
|
\code{(\var{arg}, \var{dirname}, \var{names})} for each directory in the
|
|
directory tree rooted at \var{p} (including \var{p} itself, if it is a
|
|
directory). The argument \var{dirname} specifies the visited directory,
|
|
the argument \var{names} lists the files in the directory (gotten from
|
|
\code{posix.listdir(\var{dirname})}).
|
|
The \var{visit} function may modify \var{names} to
|
|
influence the set of directories visited below \var{dirname}, e.g., to
|
|
avoid visiting certain parts of the tree. (The object referred to by
|
|
\var{names} must be modified in place, using \code{del} or slice
|
|
assignment.)
|
|
\end{funcdesc}
|