os.path.expandvars(path) Return the argument with environment variables expanded. Substrings of the form $name or ${name} are replaced by the value of environment variable name. Malformed variable names and references to non-existing variables are left unchanged. On Windows, %name% expansions are supported in addition to $name and ${name}.

do_HEAD() This method serves the 'HEAD' request type: it sends the headers it would send for the equivalent GET request. See the do_GET() method for a more complete explanation of the possible headers.

class socketserver.ThreadingMixIn Forking and threading versions of each type of server can be created using these mix-in classes. For instance, ThreadingUDPServer is created as follows: class ThreadingUDPServer(ThreadingMixIn, UDPServer): pass The mix-in class comes first, since it overrides a method defined in UDPServer. Setting the various attributes also changes the behavior of the underlying server mechanism.

glob.escape(pathname) Escape all special characters ('?', '*' and '['). This is useful if you want to match an arbitrary literal string that may have special characters in it. Special characters in drive/UNC sharepoints are not escaped, e.g. on Windows escape('//?/c:/Quo vadis?.txt') returns '//?/c:/Quo vadis[?].txt'. New in version 3.4.

IMAP4.xatom(name[, ...]) Allow simple extension commands notified by server in CAPABILITY response.

tuple([iterable]) Rather than being a function, tuple is actually an immutable sequence type, as documented in Tuples and Sequence Types — list, tuple, range.

exception mailbox.ExternalClashError Raised when some mailbox-related condition beyond the control of the program causes it to be unable to proceed, such as when failing to acquire a lock that another program already holds a lock, or when a uniquely-generated file name already exists.

IMAP4.list([directory[, pattern]]) List mailbox names in directory matching pattern. directory defaults to the top-level mail folder, and pattern defaults to match anything. Returned data contains a list of LIST responses.

close() MH instances do not keep any open files, so this method is equivalent to unlock().

FTP.pwd() Return the pathname of the current directory on the server.