if __name__ == '__main__':
    import timeit

    tries = 1000000
    tests = [
        'def count_capitals(word):return sum([1 for _ in word if _.isupper()]);count_capitals("string.ascii_uppercase * 1000000")',
        'def count_capitals(word):return len([1 for _ in word if _.isupper()]);count_capitals("string.ascii_uppercase * 1000000")',
        'def count_capitals(word):return len([_ for _ in word if _.isupper()]);count_capitals("string.ascii_uppercase * 1000000")',
        'def count_capitals(word):return len([c for c in word if c.isupper()]);count_capitals("string.ascii_uppercase * 1000000")',
        'def count_capitals(word):return sum(_.isupper() for _ in word);count_capitals("string.ascii_uppercase * 1000000")',
        'def count_capitals(word):return sum(map(str.isupper, s));count_capitals("string.ascii_uppercase * 1000000")',
    ]

    for test in tests:
        r = timeit.timeit(test, number=tries)
        test = test.replace('def count_capitals(word):return ', '')
        print(f"{test[:test.index(';')]:<40s}{r}")

# sum([1 for _ in word if _.isupper()])   0.25757529999999984
# len([1 for _ in word if _.isupper()])   0.20968720000000007
# len([_ for _ in word if _.isupper()])   0.15788329999999995
# len([c for c in word if c.isupper()])   0.1378284999999999
# sum(_.isupper() for _ in word)          0.15373329999999985
# sum(map(str.isupper, s))                0.1981145999999998