擅长:python、mysql、java
<p>IIUC,您的函数需要if else块:</p>
<pre><code>def get_date_list(x):
if not pd.isna(x['Month1']):
return ",".join(
item.strftime("%b %Y")
for item in pd.date_range(x['Month1'], x['Month2'], freq="MS")
)
return np.nan
df['Month_list'] = df.apply(lambda x: get_date_list(x), axis=1)
</code></pre>
<hr/>
<pre><code>print(df)
Month1 Month2 Month_list
0 Mar2020 Dec2020 Mar 2020,Apr 2020,May 2020,Jun 2020,Jul 2020,A...
1 Nov2020 Jan2021 Nov 2020,Dec 2020,Jan 2021
2 NaN NaN NaN
3 Sep2020 Feb2021 Sep 2020,Oct 2020,Nov 2020,Dec 2020,Jan 2021,F...
4 Oct2020 Dec2020 Oct 2020,Nov 2020,Dec 2020
5 NaN NaN NaN
6 Dec2020 Mar2021 Dec 2020,Jan 2021,Feb 2021,Mar 2021
</code></pre>