擅长:python、mysql、java
<p>需要<a href="http://pandas.pydata.org/pandas-docs/stable/generated/pandas.Series.ffill.html" rel="nofollow noreferrer">^{<cd1>}</a>:</p>
<pre><code>df['State'] = df['State'].ffill()
print (df)
State RegionName
0 Alabama Alabama
1 Alabama Auburn
2 Alabama Florence
3 Alabama Jacksonville
4 Alabama Livingston
5 Alabama Montevallo
6 Alabama Troy
7 Alabama Tuscaloosa
8 Alabama Tuskegee
9 Alaska Alaska
10 Alaska Fairbanks
11 Arizona Arizona
12 Arizona Flagstaff
13 Arizona Tempe
14 Arizona Tucson
</code></pre>