擅长:python、mysql、java
<p>似乎可以使用<a href="http://pandas.pydata.org/pandas-docs/stable/generated/pandas.DataFrame.mask.html" rel="nofollow noreferrer">^{<cd1>}</a>,比较由<a href="http://pandas.pydata.org/pandas-docs/stable/generated/pandas.DataFrame.values.html" rel="nofollow noreferrer">^{<cd3>}</a>创建的<code>numpy array</code>,替换为<code>mean</code>,最后将所有列强制转换为<code>float</code>:</p>
<pre><code>print (df.mean(axis=1))
Estonia 10.26
Spain 210.82
SlovakRepublic 29.70
Slovenia 13.68
df = df.mask(df.values == '..', df.mean(axis=1), axis=0).astype(float)
print (df)
1971 1990 1999 2000 2001 2002
Estonia 10.26 17.4 8.3 8.5 8.5 8.6
Spain 61.6 151.2 205.9 222.2 233.2 241.6
SlovakRepublic 10.9 25.5 28.1 30.8 31.9 32.2
Slovenia 13.68 12.4 13.3 13.6 14.5 14.6
</code></pre>