In this article, we will discuss how to merge the two dataframes with different lengths in Pandas. It can be done using the merge() method.
Syntax:
DataFrame.merge(parameters)
Below are some examples that depict how to merge data frames of different lengths using the above method:
Example 1:
Below is a program to merge two student data frames of different lengths.
Python3
# importing pandas module import pandas as pd # create a list that contains # student id of subject 1list1 = [7058, 7059, 7075, 7076] # create a list that contains# student id of subject 2list2 = [7058, 7059, 7012, 7075, 7076] # create a list that contains # student names of subject 1list11 = ["Sravan", "Jyothika", "Deepika", "Kyathi"] # create a list that contains # student names of subject 2list22 = ["Sravan", "Jyothika", "Salma", "Deepika", "Kyathi"] # pass list1 and list11 to the# dataframe1dataframe1 = pd.DataFrame( {"Student ID": list1, "Student Name": list11})print('First data frame:')display(dataframe1) # pass list2 and list22 to the# dataframe1dataframe2 = pd.DataFrame( {"Student ID": list2, "Student Name": list22})print('Second data frame:')display(dataframe2) # apply merge function to merge the# two dataframesmergedf = dataframe2.merge(dataframe1, how='left')print('Merged data frame:')display(mergedf) |
Output:
Example 2:
Here is another program to merge one data frame of length 4 and another dataframe of length 9.
Python3
# importing pandas moduleimport pandas as pd # create a list that contains# student id of subject 1list1 = [7058, 7059, 7075, 7076] # create a list that contains# student id of subject 2list2 = [7058, 7059, 7012, 7075, 7076, 7034, 7046, 7036, 7015] # create a list that contains# student names of subject 1list11 = ["Sravan", "Jyothika", "Deepika", "Kyathi"] # create a list that contains# student names of subject 2list22 = ["Sravan", "Jyothika", "salma", "Deepika", "Kyathi", "meghana", "pranathi", "bhanu", "keshav"] # pass list1 and list11 to the# dataframe1dataframe1 = pd.DataFrame( {"Student ID": list1, "Student Name": list11})print('First data frame:')display(dataframe1) # pass list2 and list22 to the # dataframe1dataframe2 = pd.DataFrame( {"Student ID": list2, "Student Name": list22})print('Second data frame:')display(dataframe2) # apply merge function to merge# the two dataframesmergedf = dataframe2.merge(dataframe1, how='inner')print('Merged data frame:')display(mergedf) |
Output:
