擅长:python、mysql、java
<p>使用pandas-merge-df,然后按如下所述创建一个或多个新列(仅求两列之和)怎么样
join-left=maindf,right=df,how='left',left\u on='key',right\u on='key'</p>
<pre><code>import pandas as pd
df = pd.DataFrame({'$a':[1,2], '$b': [10,20]}) # creating fake df
df2 = pd.DataFrame({'$a':[1,2], '$b': [10,20]}
dfMerge = pd.merge(left=df, right=df2, how='left', left_on='$a', right_on='$a')
dfMerge["SUM"] = dfMergeTemp["$b_x"] + dfMergeTemp["$b_y"]
# print(dfMergeTemp)
</code></pre>
<p>在您的情况下(也许重命名您的列是有意义的,不要混淆正在发生的事情)</p>
<pre><code>mergedDf = pd.merge(left = maindf, right = df, how = 'left', left_on='key', right_on = 'key')
</code></pre>