Split a String into Text and Number in Python

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Borislav Hadzhiev

Last updated: Apr 8, 2024
5 min

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# Table of Contents

  1. Split a string into text and number in Python
  2. Splitting each string in a list into text and number
  3. Split a string into text and number using a for loop
  4. Split a string into text and number using re.match()
  5. Split a string into text and number using str.rstrip()
  6. Split a string into text and number using re.findall()

# Split a string into text and number in Python

Use the re.split() method to split a string into text and number.

The re.split() method will split the string on the digits and will still include them in the list.

main.py
import re

my_str = 'hello123'

my_list = re.split(r'(\d+)', my_str)

# 👇️ ['hello', '123', '']
print(my_list)

split string into text and number

The code for this article is available on GitHub

Notice that we got an empty string at the end because the last character in the string is a digit.

You can use the filter() method to remove any empty strings from the list if there are any.

main.py
import re

my_str = 'hello123'

my_list = list(filter(None, re.split(r'(\d+)', my_str)))

# 👇️ ['hello', '123']
print(my_list)

The filter function takes a function and an iterable as arguments and constructs an iterator from the elements of the iterable for which the function returns a truthy value.

If you pass None for the function argument, all falsy elements of the iterable are removed.

The re.split method takes a pattern and a string and splits the string on each occurrence of the pattern.

The parentheses in the regular expression match whatever is inside and indicate the start and end of a group.
main.py
import re

my_str = 'hello123'

my_list = list(filter(None, re.split(r'(\d+)', my_str)))

# 👇️ ['hello', '123']
print(my_list)
The code for this article is available on GitHub

The group's contents can still be retrieved after the match.

Even though we split the string by one or more digits, we still include the digits in the result.

The \d character matches the digits in the range from 0 to 9 (and many other digit characters).

The plus + causes the regular expression to match 1 or more repetitions of the preceding character (the range of digits).

In other words, we match one or more digits using a group and still include them in the list of strings.

This approach also works if your string starts with digits and ends in characters.

main.py
import re

my_str = '123hello'

my_list = list(filter(None, re.split(r'(\d+)', my_str)))

# 👇️ ['123', 'hello']
print(my_list)

If we didn't use the filter() function, we'd have an empty string element at the start of the list.

Note that the filter function returns a filter object (not a list). If you need to convert the filter object to a list, pass it to the list() class.

# Splitting each string in a list into text and number

If you have a list of strings that you need to split into text and number, use a list comprehension.

main.py
import re

my_list = ['123ab', '456cd', '789ef']

result = [
    list(filter(None, re.split(r'(\d+)', item)))
    for item in my_list
]

# 👇️ [['123', 'ab'], ['456', 'cd'], ['789', 'ef']]
print(result)

splitting each string in list into text and number

The code for this article is available on GitHub

We used a list comprehension to iterate over the list and used the re.split() method to split each string into text and numbers.

List comprehensions are used to perform some operation for every element or select a subset of elements that meet a condition.

# Split a string into text and number using a for loop

You can also use a for loop to split a string into text and a number.

main.py
def split_text_number(string):
    letters = ''

    numbers = ''

    for char in string:
        if char.isalpha():
            letters += char
        elif char.isdigit():
            numbers += char

    return [letters, numbers]


print(split_text_number('abc123'))  # ['abc', '123']
print(split_text_number('123abc'))  # ['abc', '123']

split string into text and number using for loop

The code for this article is available on GitHub

We used a for loop to iterate over the string.

The str.isalpha() method returns True if all characters in the string are alphabetic and there is at least one character, otherwise False is returned.

main.py
print('BOBBY'.isalpha())  # 👉️ True

The str.isalpha method considers alphabetic characters as the ones that are defined in the Unicode character database as "Letter".

The str.isdigit method returns True if all characters in the string are digits and there is at least 1 character, otherwise False is returned.

The last step is to wrap the letters and digits into a list and return the result.

The code sample only adds the letters and numbers to the results.

Alternatively, you can just extract the numbers and return a string containing the rest.

main.py
def split_text_number(string):
    letters = ''

    numbers = ''

    for char in string:
        if char.isdigit():
            numbers += char
        else:
            letters += char

    return [letters, numbers]


print(split_text_number('abc123'))  # ['abc', '123']
print(split_text_number('123abc'))  # ['abc', '123']

print(split_text_number('abc123.<#'))  # ['abc.<#', '123']

When using this approach, the punctuation is also added to the letters string.

# Split a string into text and number using re.match()

You can also use the re.match() method to split a string into a text and a number.

main.py
import re

my_str = 'hello123'

match = re.match(r'([a-zA-Z]+)([0-9]+)', my_str)

my_list = []

if match is not None:
    my_list = list(match.groups())

print(my_list)  # 👉️ ['hello', '123']

split string into text and number using re match

The code for this article is available on GitHub

The re.match() method returns a match object if the provided regular expression is matched in the string.

The match() method returns None if the string doesn't match the regex pattern.

The regular expression we passed to the match() method matches one or more lowercase or uppercase letters followed by one or more digits.

The match.groups() method returns a tuple, so we used the list() class to convert the result to a list.

# Split a string into text and number using str.rstrip()

You can also use the string.rstrip() method to split a string into text and a number.

main.py
def split_into_str_num(string):
    letters = string.rstrip('0123456789')
    numbers = string[len(letters):]

    return [letters, numbers]


my_str = 'hello123'

# 👇️ ['hello', '123']
print(split_into_str_num(my_str))
The code for this article is available on GitHub

The str.rstrip() method takes a string containing characters as an argument and returns a copy of the string with the specified trailing characters removed.

main.py
my_str = 'bobbyhadz.com'

result = my_str.rstrip('ocm.')
print(result)  # 👉️ 'bobbyhadz'

We used the method to remove the digits from the end of the string and got a string containing only the letters.

The next step is to use string slicing to get the remainder of the string (the digits).

main.py
numbers = string[len(letters):]

The length of the string of letters is used to determine the start index in the slice.

# Split a string into text and number using re.findall()

You can also use the re.findall() method to split a string into text and number.

main.py
import re

def split_text_number(string):
    return list(re.findall(r'(\w+?)(\d+)', string)[0])


print(split_text_number('abc123'))  # ['abc', '123']
The code for this article is available on GitHub

The re.findall() method takes a pattern and a string as arguments and returns a list of strings containing all non-overlapping matches of the pattern in the string.

main.py
import re

# 👇️ [('abc', '123')]
print(
    re.findall(r'(\w+?)(\d+)', 'abc123')
)

The \w character matches:

  • characters that can be part of a word in any language
  • numbers
  • the underscore character

The \d character matches the digits [0-9] (and many other digit characters).

The method returns a list containing a tuple with the matches, so we accessed the list at index 0 and converted the tuple to a list.

main.py
import re

def split_text_number(string):
    return list(re.findall(r'(\w+?)(\d+)', string)[0])


print(split_text_number('abc123'))  # ['abc', '123']

Note that this approach should not be used if your string starts with digits because the \w character would match the digit at the start.

main.py
import re


def split_text_number(string):
    return list(re.findall(r'(\w+?)(\d+)', string)[0])


print(split_text_number('123abc'))  # ['1', '23']
The code for this article is available on GitHub

I've also written an article on how to split a float into integer and decimal parts.

# Additional Resources

You can learn more about the related topics by checking out the following tutorials:

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