Python filters out class instances that do not belong to characters in a specified set

This article describes how to filter strings that do not belong to a character class in a specified set in python, and describes how to operate strings and collections in Python, for more information about how to filter strings in python, see the following example. Share it with you for your reference. The details are as follows:

#-*-Coding: UTF-8-*-import setsclass Keeper (object): def _ init _ (self, keep): self. keep = sets. set (map (ord, keep) def _ getitem _ (self, n): if n not in self. keep: return None return unichr (n) def _ call _ (self, s): return s. translate (self) makefilter = Keeperif _ name _ = '_ main _': just_vowels = makefilter ('aeiouy ') print just_vowels (u'four score and seven years ago ') # output: ouoeaeeyeaao print just_vowels (u'tiger, tiger burning bright') # output: ieieuii

I hope this article will help you with Python programming.