Sorting a CSV object by dates in Python

CSV stands for comma-separated values. A CSV file can be opened in Google Sheets or Excel and will be formatted as a spreadsheet. However, a CSV file is actually a plain-text file. It can also be opened with a text editor program such as Atom. In this article, we are going to see how to sort a CSV object by dates in Python

CSVs give us a good, simple way to organize data without using a database program. It’s easy to read from and write to CSV files with Python.

Steps to Read a CSV file

Step 1: In the first step to read a CSV you need to find the file.

Step 2: Import pandas library 

The pandas library is exported by using import keyword and object as pd which is a standard notation for pandas library.

Python3

import pandas as pd

Step 3: Read the CSV file by using pandas library and assign it to a variable.

The csv file ‘data.csv’ is loaded by using read_csv method present in the pandas library and stored in the variable named ‘data’ and now this variable is called a dataframe.

Python3

data = pd.read_csv('data.csv')

Step 4: Display the first 5 rows of the data by using head function.

The ‘.head()’ method is used to print the first 5 rows and ‘.tail()’ method is used to print the last 5 rows of the data file.

Python3

display(data.head())

Output:

output screenshot

Steps to sort the Data by Dates

Step 1: Convert the Date column into required date time format

You can use the parameter infer_datetime_format. Example with your sample data below:

Python3

data['date'] = pd.to_datetime(data.date, infer_datetime_format = True)
display(data.head())

Output:

output screenshot

Step 2: Use the sort_values method and giving parameter as date we sort the values by date. To get the sorted while use head function to get first 5 rows of dataInput:

Python3

data.sort_values(by = 'date', ascending = True, inplace = True)
display(data.head())

Output: