type_v_instance.py

import timeit

_ATOMIC_TYPES_LIST = [bool, int, float, str, unicode]
_ATOMIC_TYPES_SET = set(_ATOMIC_TYPES_LIST)


def is_a_type(x):
    t = type(x)
    if (t is bool or
        t is int or
        t is float or
        t is str or
        t is unicode):
        return x
    return 'UNK'

def is_a_type_l(x):
    t = type(x)
    if t in _ATOMIC_TYPES_LIST:
        return x
    return 'UNK'

def is_a_type_s(x):
    t = type(x)
    if t in _ATOMIC_TYPES_SET:
        return x
    return 'UNK'


def is_an_instance(x):
    if isinstance(x, (bool, int, float, str, unicode)):
        return x
    return 'UNK'


def run(f):
    return [f(x) for x in (True, 1, 3.2, "dog", u"cat", {})]

for x in xrange(2):
    print "is a type: "
    print timeit.timeit(lambda: run(is_a_type))
    print ""
    print "is a type (list): "
    print timeit.timeit(lambda: run(is_a_type_l))
    print ""
    print "is a type (set): "
    print timeit.timeit(lambda: run(is_a_type_s))
    print ""
    print "is an instance: "
    print timeit.timeit(lambda: run(is_an_instance))
    print ""

# Output
# 
# is a type: 
# 2.10327100754
# 
# is a type (list): 
# 1.94879198074
# 
# is a type (set): 
# 1.77079796791
# 
# is an instance: 
# 3.94516301155
# 
# is a type: 
# 2.12281799316
# 
# is a type (list): 
# 1.96864295006
# 
# is a type (set): 
# 1.74609208107
# 
# is an instance: 
# 3.95978212357