How to group / count date data by the same check in date and check out date in python?-CodePudding

I'm trying to group the date data based on the same check in and check out date, for example:

import pandas as pd

guess = [1, 2, 3, 4, 5]
check_in = ['17/07/2021', '17/07/2021','17/07/2021', '18/07/2021','18/07/2021']
check_out = ['20/07/2021', '20/07/2021','22/07/2021', '24/07/2021', '24/07/2021' ]
data = pd.DataFrame({'guess':guess, 'check in date': check_in, 'check out date': check_out})

>>> data

I want to group those data by the same check in and the same check out date, like this (the expected output):

is there any function or library in python that can help me group this type of data?? thanku

CodePudding user response：

First use groupby() using your desired columns followed by size():

data.groupby(['check in date', 'check out date']).size()

Output:

check in date  check out date
17/07/2021     20/07/2021        2
               22/07/2021        1
18/07/2021     24/07/2021        2