擅长:python、mysql、java
<p>将合法字符放入一个集合中,然后使用<a href="https://docs.python.org/3/reference/expressions.html?highlight=membership#membership-test-operations" rel="nofollow">^{<cd1>}</a>测试字符串的每个字符。使用<a href="https://docs.python.org/3/library/stdtypes.html#str.join" rel="nofollow">^{<cd2>}</a>方法和<a href="https://docs.python.org/3/reference/expressions.html#conditional-expressions" rel="nofollow">conditional expression</a>构造新字符串。在</p>
<pre><code>>>> s = "test.,/?~abcdefgh"
>>> legal = set('.,/?~abcdefg')
>>> s = ''.join(char if char in legal else '?' for char in s)
>>> s
'?e??.,/?~abcdefg?'
>>>
</code></pre>