擅长:python、mysql、java
<p><a href="https://docs.python.org/2/library/string.html#formatstrings" rel="noreferrer">format string syntax</a>声明<code>:</code>引入了格式说明符<a href="https://docs.python.org/2/library/string.html#formatspec" rel="noreferrer">which is defined as follows</a>:</p>
<pre><code>format_spec ::= [[fill]align][sign][#][0][width][,][.precision][type]
</code></pre>
<p>所有元素都是可选的,以及</p>
<blockquote>
<p>The '<code>,</code>' option signals the use of a comma for a thousands separator. For a locale aware separator, use the '<code>n</code>' integer presentation type instead.</p>
</blockquote>