python正则表达式：如何根据字母，数字和标点符号将字符串拆分为不同的组

Question

I am learning regular expressions using python 2.7

Given a sentence(assume lowercase and ascii) such as:

input = 'i like: a, b, 007 and c!!'

How would I tokenize the input string into

['i', 'like', ':', 'a', ',', 'b', ',', '007', 'and', 'c', '!!']

I can write the automata and code the transition matrix in C++, but I would like to do this in python

I am unable to come up with a regex that will match these distinct classes of alphabets, digits and punctuations in one go.

I have seen a couple of stackoverflow posts here and here , but do not quite follow their approaches.

I have tried this for some time now and I would appreciate your help on this.

PS: This is not a homework question

Answer 1

>>> from string import punctuation
>>> text = 'i like: a, b, 007 and c!!'
>>> re.findall('\w+|[{0}]+'.format(punctuation),text)
['i', 'like', ':', 'a', ',', 'b', ',', '007', 'and', 'c', '!!']

This also works but finds any non-whitespace character if it doesn't find alphanumeric characters

>>> re.findall('\w+|\S+',text)
['i', 'like', ':', 'a', ',', 'b', ',', '007', 'and', 'c', '!!']