擅长:python、mysql、java
<p>使用<code>applymap</code>新建列:</p>
<pre><code>import pandas as pd
dates = [
20160228,
20161231,
20160618,
20170123,
20151124,
]
df = pd.DataFrame(data=list(enumerate(dates, start=1)), columns=['id','int_date'])
df[['str_date']] = df[['int_date']].applymap(str).applymap(lambda s: "{}/{}/{}".format(s[4:6],s[6:], s[0:4]))
print(df)
</code></pre>
<p>发射:</p>
<pre><code>$ python test.py
id int_date str_date
0 1 20160228 02/28/2016
1 2 20161231 12/31/2016
2 3 20160618 06/18/2016
3 4 20170123 01/23/2017
4 5 20151124 11/24/2015
</code></pre>