擅长:python、mysql、java
<p>IIUC<a href="https://pandas.pydata.org/pandas-docs/stable/generated/pandas.DataFrame.merge.html" rel="nofollow noreferrer">^{<cd1>}</a></p>
<pre><code>nocity.merge(withcity,on='business_id',how='left')
Out[855]:
user_id business_id stars city
0 cjpdDjZyprfyDG3RlkVG3w uYHaNptLzDLoV_JZ_MuzUA 5 NaN
1 bjTcT8Ty4cJZhEOEo01FGA uYHaNptLzDLoV_JZ_MuzUA 3 NaN
2 AXgRULmWcME7J6Ix3I ww uYHaNptLzDLoV_JZ_MuzUA 3 NaN
3 oU2SSOmsp_A8JYI7Z2JJ5w uYHaNptLzDLoV_JZ_MuzUA 4 NaN
4 0xtbPEna2Kei11vsU-U2Mw uYHaNptLzDLoV_JZ_MuzUA 5 NaN
</code></pre>