Python Read Text File

Summary: in this tutorial, you learn various ways to read text files in Python.

TL;DR

The following shows how to read all texts from the readme.txt file into a string:

with open('readme.txt') as f: lines = f.readlines()
Code language: JavaScript (javascript)

Steps for reading a text file in Python

To read a text file in Python, you follow these steps:

  • First, open a text file for reading by using the open() function.
  • Second, read text from the text file using the file read(), readline(), or readlines() method of the file object.
  • Third, close the file using the file close() method.

1) open() function

The open() function has many parameters but you’ll be focusing on the first two.

open(path_to_file, mode)

The path_to_file parameter specifies the path to the text file.

If the file is in the same folder as the program, you just need to specify the name of the file. Otherwise, you need to specify the path to the file.

To specify the path to the file, you use the forward-slash ('/') even if you’re working in Windows.

For example, if the file is readme.txt stored in the sample folder as the program, you need to specify the path to the file as c:/sample/readme.txt

The mode is an optional parameter. It’s a string that specifies the mode in which you want to open the file.

The following table shows available modes for opening a text file:

ModeDescription
'r'Open for text file for reading text
'w'Open a text file for writing text
'a'Open a text file for appending text

For example, to open a file whose name is the-zen-of-python.txt stored in the same folder as the program, you use the following code:

f = open('the-zen-of-python.txt','r')
Code language: JavaScript (javascript)

The open() function returns a file object which you will use to read text from a text file.

2) Reading text methods

The file object provides you with three methods for reading text from a text file:

  • read() – read all text from a file into a string. This method is useful if you have a small file and you want to manipulate the whole text of that file.
  • readline() – read the text file line by line and return all the lines as strings.
  • readlines() – read all the lines of the text file and return them as a list of strings.

3) close() method

The file that you open will remain open until you close it using the close() method.

It’s important to close the file that is no longer in use. If you don’t close the file, the program may crash or the file would be corrupted.

The following shows how to call the close() method to close the file:

f.close()
Code language: CSS (css)

To close the file automatically without calling the close() method, you use the with statement like this:

with open(path_to_file) as f: contents = f.readlines()
Code language: JavaScript (javascript)

In practice, you’ll use the with statement to close the file automatically.

Reading a text file examples

We’ll use the-zen-of-python.txt file for the demonstration.

The following example illustrates how to use the read() method to read all the contents of the the-zen-of-python.txt file into a string:

with open('the-zen-of-python.txt') as f: contents = f.read() print(contents)
Code language: JavaScript (javascript)

Output:

Beautiful is better than ugly. Explicit is better than implicit. Simple is better than complex. ...

The following example uses the readlines() method to read the text file and returns the file contents as a list of strings:

lines = [] with open('the-zen-of-python.txt') as f: lines = f.readlines() count = 0 for line in lines: count += 1 print(f'line {count}: {line}')
Code language: JavaScript (javascript)

Output:

line 1: Beautiful is better than ugly. line 2: Explicit is better than implicit. line 3: Simple is better than complex. ...

The following example shows how to use the readline() to read the text file line by line:

with open('the-zen-of-python.txt') as f: line = f.readline() while line: line = f.readline() print(line)
Code language: JavaScript (javascript)

Output:

Explicit is better than implicit. Simple is better than complex. Complex is better than complicated. ...

A more concise way to read a text file line by line

The open() function returns a file object which is an iterable object. Therefore, you can use a for loop to iterate over the lines of a text file as follows:

with open('the-zen-of-python.txt') as f: for line in f: print(line)
Code language: JavaScript (javascript)

This is more concise way to read a text file line by line.

Read UTF-8 text files

The code in the previous examples works fine with ASCII text files. However, if you’re dealing with other languages such as Japanese, Chinese, and Korean, the text file is not a simple ASCII text file. And it’s likely a UTF-8 file that uses more than just the standard ASCII text characters.

To open a UTF-8 text file, you need to pass the encoding='utf-8' to the open() function to instruct it to expect UTF-8 characters from the file.

For the demonstration, you’ll use the following quotes.txt file that contains some quotes in Japanese.

The following shows how to loop through the quotes.txt file:

with open('quotes.txt', encoding='utf8') as f: for line in f: print(line.strip())
Code language: JavaScript (javascript)

Output:

Python read utf-8 text file

Summary

  • Use the open() function with the 'r' mode to open a text file for reading.
  • Use the read(), readline(), or readlines() method to read a text file.
  • Always close a file after completing reading it using the close() method or the with statement.
  • Use the encoding='utf-8' to read the UTF-8 text file.
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