The output of the following invocations are exactly the same:

list(shlex.shlex('a ; b', posix=True, punctuation_chars=True))

list(shlex.shlex('a \; b', posix=True, punctuation_chars=True))

They both output the following:

['a', ';', 'b']

This makes it impossible to determine when the user wanted to escape the semi-colon for some reason, such as if they were using find's `-exec` argument.