擅长:python、mysql、java
<p>IIUC</p>
<pre><code>s=(df.date1-pd.to_datetime(date,format='%Y%m'))//np.timedelta64(1, 'M')+1
Out[118]:
0 1
1 2
2 3
3 4
4 5
Name: date1, dtype: int64
df['months']=s
</code></pre>
<p>更新</p>
<pre><code>(df.date1.dt.year*12+df.date1.dt.month)-(pd.to_numeric(date)//100)*12-(pd.to_numeric(date)%100)+1
Out[379]:
0 1
1 2
2 3
3 4
4 5
5 20
6 21
Name: date1, dtype: int64
</code></pre>