从字符串中过滤字符 [英] Filtering Characters from a String

问题描述

我需要制作一个函数，将两个字符串作为输入，并返回str 1的副本，其中删除了str2中的所有字符.

I need to make a function that takes two strings as imnput and returns a copy of str 1 with all characters from str2 removed.

第一件事是使用for循环在str1上进行迭代，然后与str2进行比较，要完成减法运算，我应该创建一个第三个字符串来存储输出，但是在那之后我有点迷失了.

First thing is to iterate over str1 with a for loop, then compare to str2, to accomplish subtraction I should create a 3rd string in which to store the output but I'm a little lost after that.

def filter_string(str1, str2):
    str3 = str1   
    for character in str1:
       if character in str2:
           str3 = str1 - str2
    return str3

这就是我一直在玩的游戏，但我不知道该如何进行.

This is what I've been playing with but I don't understand how I should proceed.

推荐答案

只需使用来自文档:

string.translate(s, table[, deletechars])

删除deletechars 中的所有s字符(如果存在)，然后使用table转换字符，该字符必须为256个字符的字符串，并提供以下内容的翻译每个字符值，按其序号索引. 如果table为None，则仅执行字符删除步骤.

Delete all characters from s that are in deletechars (if present), and then translate the characters using table, which must be a 256-character string giving the translation for each character value, indexed by its ordinal. If table is None, then only the character deletion step is performed.

如果出于教育目的，您想自己编写代码，则可以使用以下代码:

If -- for educational purposes -- you'd like to code it up yourself, you could use something like:

''.join(c for c in str1 if c not in str2)

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