how to compare same columns in two dataframes pandas code example

Example 1: pandas compare two columns of different dataframe

df1['priceDiff?'] = np.where(df1['Price1'] == df2['Price2'], 0, df1['Price1'] - df2['Price2'])

Example 2: pandas compare two columns of different dataframe

import numpy as np
df1['low_value'] = np.where(df1.value <= df2.low, 'True', 'False')