os module

abort(...)
        abort() -> does not return!
       
        Abort the interpreter immediately.  This 'dumps core' or otherwise fails
        in the hardest way possible on the hosting operating system.
   
access(...)
        access(path, mode) -> True if granted, False otherwise
       
        Use the real uid/gid to test for access to a path.  Note that most
        operations will use the effective uid/gid, therefore this routine can
        be used in a suid/sgid environment to test if the invoking user has the
        specified access to the path.  The mode argument can be F_OK to test
        existence, or the inclusive-OR of R_OK, W_OK, and X_OK.
   
chdir(...)
        chdir(path)
       
        Change the current working directory to the specified path.
   
chmod(...)
        chmod(path, mode)
       
        Change the access permissions of a file.
   
    close(...)
        close(fd)
       
        Close a file descriptor (for low level IO).
   
    closerange(...)
        closerange(fd_low, fd_high)
       
        Closes all file descriptors in [fd_low, fd_high), ignoring errors.
   
    device_encoding(...)
        device_encoding(fd) -> str
       
        Return a string describing the encoding of the device
        if the output is a terminal; else return None.
   
    dup(...)
        dup(fd) -> fd2
       
        Return a duplicate of a file descriptor.
   
    dup2(...)
        dup2(old_fd, new_fd)
       
        Duplicate file descriptor.
   
    execl(file, *args)
        execl(file, *args)
       
        Execute the executable file with argument list args, replacing the
        current process.
   
    execle(file, *args)
        execle(file, *args, env)
       
        Execute the executable file with argument list args and
        environment env, replacing the current process.
   
    execlp(file, *args)
        execlp(file, *args)
       
        Execute the executable file (which is searched for along $PATH)
        with argument list args, replacing the current process.
   
    execlpe(file, *args)
        execlpe(file, *args, env)
       
        Execute the executable file (which is searched for along $PATH)
        with argument list args and environment env, replacing the current
        process.
   
    execv(...)
        execv(path, args)
       
        Execute an executable path with arguments, replacing current process.
       
            path: path of executable file
            args: tuple or list of strings
   
    execve(...)
        execve(path, args, env)
       
        Execute a path with arguments and environment, replacing current process.
       
            path: path of executable file
            args: tuple or list of arguments
            env: dictionary of strings mapping to strings
   
    execvp(file, args)
        execvp(file, args)
       
        Execute the executable file (which is searched for along $PATH)
        with argument list args, replacing the current process.
        args may be a list or tuple of strings.
   
    execvpe(file, args, env)
        execvpe(file, args, env)
       
        Execute the executable file (which is searched for along $PATH)
        with argument list args and environment env , replacing the
        current process.
        args may be a list or tuple of strings.
   
    fstat(...)
        fstat(fd) -> stat result
       
        Like stat(), but for an open file descriptor.
   
    fsync(...)
        fsync(fildes)
       
        force write of file with filedescriptor to disk.
    
    getcwd(...)
        getcwd() -> path
       
        Return a unicode string representing the current working directory.
   
    getcwdb(...)
        getcwdb() -> path
       
        Return a bytes string representing the current working directory.
   
    getenv(key, default=None)
        Get an environment variable, return None if it doesn't exist.
        The optional second argument can specify an alternate default.
        key, default and the result are str.
   
    getlogin(...)
        getlogin() -> string
       
        Return the actual login name.
   
    getpid(...)
        getpid() -> pid
       
        Return the current process id
   
    getppid(...)
        getppid() -> ppid
       
        Return the parent's process id.  If the parent process has already exited,
        Windows machines will still return its id; others systems will return the id
        of the 'init' process (1).
   
    isatty(...)
        isatty(fd) -> bool
       
        Return True if the file descriptor 'fd' is an open file descriptor
        connected to the slave end of a terminal.
   
    kill(...)
        kill(pid, sig)
       
        Kill a process with a signal.
   
    link(...)
        link(src, dst)
       
        Create a hard link to a file.
   
    listdir(...)
        listdir([path]) -> list_of_strings
       
        Return a list containing the names of the entries in the directory.
       
            path: path of directory to list (default: '.')
       
        The list is in arbitrary order.  It does not include the special
        entries '.' and '..' even if they are present in the directory.
   
    lseek(...)
        lseek(fd, pos, how) -> newpos
       
        Set the current position of a file descriptor.
   
    lstat(...)
        lstat(path) -> stat result
       
        Like stat(path), but do not follow symbolic links.
   
    makedirs(name, mode=511, exist_ok=False)
        makedirs(path [, mode=0o777][, exist_ok=False])
       
        Super-mkdir; create a leaf directory and all intermediate ones.
        Works like mkdir, except that any intermediate path segment (not
        just the rightmost) will be created if it does not exist. If the
        target directory with the same mode as we specified already exists,
        raises an OSError if exist_ok is False, otherwise no exception is
        raised.  This is recursive.
   
    mkdir(...)
        mkdir(path [, mode=0777])
       
        Create a directory.
   
    open(...)
        open(filename, flag [, mode=0777]) -> fd
       
        Open a file (for low level IO).
   
    pipe(...)
        pipe() -> (read_end, write_end)
       
        Create a pipe.
   
    putenv(...)
        putenv(key, value)
       
        Change or add an environment variable.
   
    read(...)
        read(fd, buffersize) -> string
       
        Read a file descriptor.
   
    readlink(...)
        readlink(path) -> path
       
        Return a string representing the path to which the symbolic link points.
   
    remove(...)
        remove(path)
       
        Remove a file (same as unlink(path)).
   
    removedirs(name)
        removedirs(path)
       
        Super-rmdir; remove a leaf directory and all empty intermediate
        ones.  Works like rmdir except that, if the leaf directory is
        successfully removed, directories corresponding to rightmost path
        segments will be pruned away until either the whole path is
        consumed or an error occurs.  Errors during this latter phase are
        ignored -- they generally mean that a directory was not empty.
   
    rename(...)
        rename(old, new)
       
        Rename a file or directory.
   
    renames(old, new)
        renames(old, new)
       
        Super-rename; create directories as necessary and delete any left
        empty.  Works like rename, except creation of any intermediate
        directories needed to make the new pathname good is attempted
        first.  After the rename, directories corresponding to rightmost
        path segments of the old name will be pruned way until either the
        whole path is consumed or a nonempty directory is found.
       
        Note: this function can fail with the new directory structure made
        if you lack permissions needed to unlink the leaf directory or
        file.
   
    rmdir(...)
        rmdir(path)
       
        Remove a directory.
   
    spawnl(mode, file, *args)
        spawnl(mode, file, *args) -> integer
       
        Execute file with arguments from args in a subprocess.
        If mode == P_NOWAIT return the pid of the process.
        If mode == P_WAIT return the process's exit code if it exits normally;
        otherwise return -SIG, where SIG is the signal that killed it.
   
    spawnle(mode, file, *args)
        spawnle(mode, file, *args, env) -> integer
       
        Execute file with arguments from args in a subprocess with the
        supplied environment.
        If mode == P_NOWAIT return the pid of the process.
        If mode == P_WAIT return the process's exit code if it exits normally;
        otherwise return -SIG, where SIG is the signal that killed it.
   
    spawnv(...)
        spawnv(mode, path, args)
       
        Execute the program 'path' in a new process.
       
            mode: mode of process creation
            path: path of executable file
            args: tuple or list of strings
   
    spawnve(...)
        spawnve(mode, path, args, env)
       
        Execute the program 'path' in a new process.
       
            mode: mode of process creation
            path: path of executable file
            args: tuple or list of arguments
            env: dictionary of strings mapping to strings
   
    startfile(...)
        startfile(filepath [, operation]) - Start a file with its associated
        application.
       
        When "operation" is not specified or "open", this acts like
        double-clicking the file in Explorer, or giving the file name as an
        argument to the DOS "start" command: the file is opened with whatever
        application (if any) its extension is associated.
        When another "operation" is given, it specifies what should be done with
        the file.  A typical operation is "print".
       
        startfile returns as soon as the associated application is launched.
        There is no option to wait for the application to close, and no way
        to retrieve the application's exit status.
       
        The filepath is relative to the current directory.  If you want to use
        an absolute path, make sure the first character is not a slash ("/");
        the underlying Win32 ShellExecute function doesn't work if it is.
   
    stat(...)
        stat(path) -> stat result
       
        Perform a stat system call on the given path.
   
    stat_float_times(...)
        stat_float_times([newval]) -> oldval
       
        Determine whether os.[lf]stat represents time stamps as float objects.
        If newval is True, future calls to stat() return floats, if it is False,
        future calls return ints.
        If newval is omitted, return the current setting.
   
    strerror(...)
        strerror(code) -> string
       
        Translate an error code to a message string.
   
    symlink(...)
        symlink(src, dst, target_is_directory=False)
       
        Create a symbolic link pointing to src named dst.
        target_is_directory is required if the target is to be interpreted as
        a directory.
        This function requires Windows 6.0 or greater, and raises a
        NotImplementedError otherwise.
   
    system(...)
        system(command) -> exit_status
       
        Execute the command (a string) in a subshell.
   
    times(...)
        times() -> (utime, stime, cutime, cstime, elapsed_time)
       
        Return a tuple of floating point numbers indicating process times.
   
    umask(...)
        umask(new_mask) -> old_mask
       
        Set the current numeric umask and return the previous umask.
   
    unlink(...)
        unlink(path)
       
        Remove a file (same as remove(path)).
   
    urandom(...)
        urandom(n) -> str
       
        Return n random bytes suitable for cryptographic use.
   
    utime(...)
        utime(path, (atime, mtime))
        utime(path, None)
       
        Set the access and modified time of the file to the given values.  If the
        second form is used, set the access and modified times to the current time.
   
    waitpid(...)
        waitpid(pid, options) -> (pid, status << 8)
       
        Wait for completion of a given process.  options is ignored on Windows.
   
    walk(top, topdown=True, onerror=None, followlinks=False)
        Directory tree generator.
       
        For each directory in the directory tree rooted at top (including top
        itself, but excluding '.' and '..'), yields a 3-tuple
       
            dirpath, dirnames, filenames
       
        dirpath is a string, the path to the directory.  dirnames is a list of
        the names of the subdirectories in dirpath (excluding '.' and '..').
        filenames is a list of the names of the non-directory files in dirpath.
        Note that the names in the lists are just names, with no path components.
        To get a full path (which begins with top) to a file or directory in
        dirpath, do os.path.join(dirpath, name).
       
        If optional arg 'topdown' is true or not specified, the triple for a
        directory is generated before the triples for any of its subdirectories
        (directories are generated top down).  If topdown is false, the triple
        for a directory is generated after the triples for all of its
        subdirectories (directories are generated bottom up).
       
        When topdown is true, the caller can modify the dirnames list in-place
        (e.g., via del or slice assignment), and walk will only recurse into the
        subdirectories whose names remain in dirnames; this can be used to prune
        the search, or to impose a specific order of visiting.  Modifying
        dirnames when topdown is false is ineffective, since the directories in
        dirnames have already been generated by the time dirnames itself is
        generated.
       
        By default errors from the os.listdir() call are ignored.  If
        optional arg 'onerror' is specified, it should be a function; it
        will be called with one argument, an os.error instance.  It can
        report the error to continue with the walk, or raise the exception
        to abort the walk.  Note that the filename is available as the
        filename attribute of the exception object.
       
        By default, os.walk does not follow symbolic links to subdirectories on
        systems that support them.  In order to get this functionality, set the
        optional argument 'followlinks' to true.
       
        Caution:  if you pass a relative pathname for top, don't change the
        current working directory between resumptions of walk.  walk never
        changes the current directory, and assumes that the client doesn't
        either.
       
        Example:
       
        import os
        from os.path import join, getsize
        for root, dirs, files in os.walk('python/Lib/email'):
            print(root, "consumes", end="")
            print(sum([getsize(join(root, name)) for name in files]), end="")
            print("bytes in", len(files), "non-directory files")
            if 'CVS' in dirs:
                dirs.remove('CVS')  # don't visit CVS directories
   
    write(...)
        write(fd, string) -> byteswritten
       
        Write a string to a file descriptor.