Files Introduction

Python has a ton of great utilities for working with files, especially text files. We’re going to go over the basics of reading from files and writing to files in this post.

Reading from Files

Reading from files in Python is very easy using the with keyword. With lets Python take care of the business of opening and closing our files, and we can just focus on getting our work done. The open function takes a file path and opens the file for you in the with context.

with open('my_file.txt') as my_file:
    # We create the my_file object and operate on it in this indented block
    file_contents = my_file.read()

print(file_contents)
# Will output the contents of the file

There are several ways to read the contents of a file, the most common will be the file.read() method and iteration.

with open('my_file.txt') as my_file:
    # my_file.read() will read all the contents of the file and assing it to the variable file_contents
    file_contents = my_file.read()

with open('my_file.txt') as my_file:
    # We can also iterate line by line with a for loop
    for line in my_file:
        print(line)
    # This will print each line of the file

Writing to Files

Writing to files is just as easy in Python using the with keyword. You just need to specify in the open function that you want to write to the file with the mode argument. Check the open function documentation for all the modes.

# Specifying 'w' as the mode means write, it defaults to read only 'r'
with open('my_file.txt', mode='w') as my_file:
    my_file.write('SearingFrost')

with open('my_file.txt') as my_file:
    searing_frost = my_file.read()

print(searing_frost)
# SearingFrost