擅长:python、mysql、java
<p>根据埃德温的回答推断:</p>
<pre><code>from math import ceil, floor
def float_round(num, places = 0, direction = floor):
return direction(num * (10**places)) / float(10**places)
</code></pre>
<p>使用:</p>
<pre><code>>>> float_round(0.21111, 3, ceil) #round up
>>> 0.212
>>> float_round(0.21111, 3) #round down
>>> 0.211
>>> float_round(0.21111, 3, round) #round naturally
>>> 0.211
</code></pre>