擅长:python、mysql、java
<p>你可以这样检查:</p>
<pre><code>my_string[:4*N] == ' ' * 4*N
</code></pre>
<p>您也可以将您的支票转换为<code>lambda</code>:</p>
^{pr2}$
<p>称之为:</p>
<pre><code>check(' asdas', 2) # -> True
check(' asdas', 3) # -> False
</code></pre>
<p>或者,如果出于任何原因想对<code>N</code>进行硬编码(<code>N = 3</code>):</p>
<pre><code>check = lambda my_string: my_string[:12] == ' ' * 12
</code></pre>
<hr/>
<blockquote>
<p>EDIT: If the <em>4Nth + 1</em> character is required to <strong>not</strong> be a space, you can incorporate that into your <code>lambda</code>:</p>
</blockquote>
<pre><code>check_strict = lambda my_string, N: my_string[:4*N] == ' ' * 4*N and my_string[4*N + 1] != ' '
</code></pre>
<p>或者</p>
<pre><code>check_strict = lambda my_string: my_string[:12] == ' ' * 12 and my_string[13] != ' '
</code></pre>