擅长:python、mysql、java
<p>您可以提供一个只替换第一次出现的参数。在</p>
<p>更改:</p>
<pre><code>a2 = a1.replace(str(num0), str(num0+1))
</code></pre>
<p>收件人:</p>
^{pr2}$
<p>如前所述:<a href="https://docs.python.org/3/library/stdtypes.html" rel="nofollow noreferrer">https://docs.python.org/3/library/stdtypes.html</a></p>
<blockquote>
<p>str.replace(old, new[, count])</p>
<p>Return a copy of the string with all occurrences of substring old replaced by new. If the optional argument count is given, only the first count occurrences are replaced.</p>
</blockquote>