Python doesn't complain if you pass a regex object into re.match but there appears to be a speed difference:
In [1]: import re
In [2]: r = re.compile('x')
In [3]: %timeit re.match(r, 'x')
The slowest run took 7.74 times longer than the fastest. This could mean that an intermediate result is being cached.
100000 loops, best of 3: 2.34 µs per loop
In [4]: %timeit r.match('x')
The slowest run took 10.88 times longer than the fastest. This could mean that an intermediate result is being cached.
1000000 loops, best of 3: 351 ns per loop
Python doesn't complain if you pass a regex object into
re.matchbut there appears to be a speed difference: