如何比较两个数据框中的两列是否存在差异？

Question

I have two DataFrames, and I need to compare two columns in my first DataFrame with two columns in another DataFrame to compare the differences in the values.

This is what my first DataFrame looks like:

item_number	sell_price
50	12
50	12
43	15
21	20
66	54
66	102
66	76

This is what my second DataFrame looks like:

item_number	price
50	15
50	15
43	15
21	28
66	87
66	87
66	78

Now, how do I compare the item_number and sell_price in my first DataFrame with the item_number and price in my second DataFrame?

I need to see the differences between the two DataFrames for the desired columns.

I am looking for an output like this:

item_number	sell_price	price
50	12	15
50	12	15
21	20	28
66	54	87
66	102	87
66	76	78

Answer 1

Here's an example:

import pandas as pd
df1=pd.DataFrame({'item_number':[10,20],'sell_price':[20,40]},index=[0,1])
df2=pd.DataFrame({'item_number':[10,20],'price':[15,20]},index=[0,1])
df1['price']=df2['price']

Note you're effectively adding a column to the original df1. You can always reassign to another df if you wish.