How to Split String by Regular Expression in Python?

Python - Split String by Regular Expression

You can split a string in Python with delimiter defined by a Regular Expression.

In this tutorial, we will learn how to split a string by a regular expression delimiter using re python package.

Examples

1. Split given string by a regular expression

In this example, we will take a string with items/words separated by a combination of underscore and comma.

So, the delimiter could be __, _,, ,_ or ,,. The regular expression to cover these delimiters is '[_,][_,]'. [_,] specifies that a character could match _ or ,.

Python Program

import re
#a string
str = '63__foo,,bar,_mango_,apple'
#split string into chunks
chunks = re.split('[_,][_,]',str)
#print chunks
print(chunks)

Output

['63', 'foo', 'bar', 'mango', 'apple']

2. Split given string by a class of characters

Regular expression classes are those which cover a group of characters. We will use one of such classes, \d which matches any decimal digit.

In this example, we will also use + which matches one or more of the previous character.

Regular expression '\d+' would match one or more decimal digits. In this example, we will use this regular expression to split a string into chunks which are separated by one or more decimal digits.

Python Program

import re

#a string
str = 'foo635bar4125mango2apple21orange'
#split with regular expression
chunks = re.split('\d+',str)
print(chunks)

Output

['foo', 'bar', 'mango', 'apple', 'orange']

Summary

In this tutorial of Python Examples, we learned how to re package to split a string using regular expressions.