擅长:python、mysql、java
<pre><code>a = [None,1,2,3,None,4,None,None]
start = next(ele for ele in a if ele is not None)
for ind, ele in enumerate(a):
if ele is None:
a[ind] = start
else:
start = ele
print(a)
[1, 1, 2, 3, 3, 4, 4, 4]
</code></pre>
<p>如果第一个元素为“无”,则只需将start设置为值:</p>
^{pr2}$