Reading and Writing Files

The file Reading/Writing process

To read/write to a file in Python, you will want to use the with statement, which will close the file for you after you are done, managing the available resources for you.

Opening and reading files

The open function opens a file and return a corresponding file object.

>>> with open('C:\\Users\\your_home_folder\\hi.txt') as hello_file:
...     hello_content = hello_file.read()
...
>>> hello_content
'Hello World!'

Alternatively, you can use the readlines() method to get a list of string values from the file, one string for each line of text:

>>> with open('sonnet29.txt') as sonnet_file:
...     sonnet_file.readlines()
...
# [When, in disgrace with fortune and men's eyes,\n',
# ' I all alone beweep my  outcast state,\n',
# And trouble deaf heaven with my bootless cries,\n', And
# look upon myself and curse my fate,']

You can also iterate through the file line by line:

>>> with open('sonnet29.txt') as sonnet_file:
...     for line in sonnet_file:
...         print(line, end='')
...
# When, in disgrace with fortune and men's eyes,
# I all alone beweep my outcast state,
# And trouble deaf heaven with my bootless cries,
# And look upon myself and curse my fate,

Writing to files

>>> with open('bacon.txt', 'w') as bacon_file:
...     bacon_file.write('Hello world!\n')
...
# 13

>>> with open('bacon.txt', 'a') as bacon_file:
...     bacon_file.write('Bacon is not a vegetable.')
...
# 25

>>> with open('bacon.txt') as bacon_file:
...     content = bacon_file.read()
...
>>> print(content)
# Hello world!
# Bacon is not a vegetable.