How to wrap long lines in Python?

In Python, we will come across situations where we encounter long lines of code that exceed the recommended line length of 79 characters (suggested by the Python style guide PEP 8).

To improve code readability, Python provides several ways to wrap long lines. In this article, we will explore the various methods to wrap long lines in Python.

Using Backslash (\)

The backslash (\) is used as the line continuation character in Python. It indicates the compiler that the statement continues on the next line. If we try to place anything (word, space or comment) after the backslash, it will result in a syntax error.

Example 1 − Valid Backslash Usage

Let's look at the following example, where we are going to use the backslash and observe the output ?

demo = 112 + 234 + 21 + 222 + 312 + \
       564 + 234
print("Result :", demo)

The output of the above program is as follows ?

Result : 1699

Example 2 − Invalid Backslash Usage

Consider another scenario, where we are going to place a space after the backslash and observe the error ?

# This will cause a syntax error due to space after backslash
try:
    # Simulating the error case
    code = '''str1 = "Hi, " + "Welcome " + "to " + \ 
       "TutorialsPoint "'''
    exec(code)
except SyntaxError as e:
    print("SyntaxError:", str(e))

The output of the above program is as follows ?

SyntaxError: unexpected character after line continuation character

Using Parentheses

Python allows the implicit line continuation inside parentheses (), brackets [], and curly braces {}. It is preferred over the backslash as it is less error-prone. We can break a long list, tuple, or dictionary across multiple lines without the need for any special character.

Example 1 − Wrapping Lists

In the following example, we are going to wrap a list across multiple lines using brackets ?

fruits = [
    "Apple", 
    "Banana", 
    "Orange", 
    "Mango", 
    "Grapes"
]
print("Fruits:", fruits)

The output of the above program is as follows ?

Fruits: ['Apple', 'Banana', 'Orange', 'Mango', 'Grapes']

Example 2 − Wrapping Function Calls

We can also wrap long function calls with multiple parameters ?

result = sum([
    112, 234, 21, 
    222, 312, 564, 
    234
])
print("Sum:", result)

The output of the above program is as follows ?

Sum: 1699

Using Python textwrap.fill() Function

In this approach, we are going to use the Python textwrap module, which provides functionality for formatting and wrapping plain text. The textwrap.fill() function accepts a long string and wraps it, making each line at the specified width.

Syntax

Following is the syntax of the Python textwrap.fill() function ?

textwrap.fill(text, width)

Example

Following is an example where we are going to use the textwrap module to wrap long text ?

import textwrap

str1 = "Welcome to the TutorialsPoint, The E-learning Platform for programming and technology tutorials."  
result = textwrap.fill(str1, width=25)
print(result)

The output of the above program is as follows ?

Welcome to the
TutorialsPoint, The E-
learning Platform for
programming and technology
tutorials.

Comparison of Methods

Conclusion

Use parentheses for wrapping code structures as it's the cleanest approach. Use backslashes sparingly for general line continuation. The textwrap module is ideal for formatting long text strings with automatic word wrapping.