PUNCTUATION_MARKS = (',','.','!','?','"\n"','"\t"' )

def count_quantity_words(text):
    count_words = 0
    for char in text:
        if char in PUNCTUATION_MARKS:
            count_words += 1
    return count_words

>>> def f(x, y):
... 	print x, y
... 	return x + y
... 
>>> reduce(f, [1, 2, 3, 4, 5])
1 2
3 3
6 4
10 5
15

reduce(lambda x, y: x+y,(1 for x in s if x in (',','.','!','?','"\n"','"\t"')), 0)

reduce(lambda x, y: x + int(y in ',.!?\n\t'), text, 0)