What's the reverse of shlex.split?

We now (3.3) have a shlex.quote function. It’s none other that pipes.quote moved and documented (code using pipes.quote will still work). See http://bugs.python.org/issue9723 for the whole discussion.

subprocess.list2cmdline is a private function that should not be used. It could however be moved to shlex and made officially public. See also http://bugs.python.org/issue1724822.

How about using pipes.quote?

import pipes
strings = ["ls", "/etc/services", "file with spaces"]
" ".join(pipes.quote(s) for s in strings)
# "ls /etc/services 'file with spaces'"

.

There is a feature request for adding shlex.join(), which would do exactly what you ask. As of now, there does not seem any progress on it, though, mostly as it would mostly just forward to shlex.quote(). In the bug report, a suggested implementation is mentioned:

' '.join(shlex.quote(x) for x in split_command)

See https://bugs.python.org/issue22454