We have a variety of ways to achieve this. We can filter out non digit characters using for ... if statement. For example:
>>> s = "H3ll0 P30P13" >>> ''.join(i for i in s if i.isdigit()) '303013'
We can also use filter and a lambda function to filter out the characters. For example:
>>> s = "H3ll0 P30P13" >>> filter(lambda x: x.isdigit(), s) '303013'
Though an overkill for such a simple task, we can also use a regex for achieving the same thing. The \D character(non digit) can be replaced by an empty string. For example:
>>> import re >>> s = "H3ll0 P30P13" >>> re.sub("\D", "", s) '303013'