This ends up with some weird code... we're using the explicit compile interface, but re-compiling on every loop. If it's really important that this be fast, then `re.compile` should be called once on a separate line and then the result used in the comprehension. (This would most closely match the `filter` behavior.) Or if it's not important that it be fast (how many thousands of entries do we expect in `sys.argv`?), then it should be written `if re.match(r'...', _m)`