How to get integer values from a string in Python?

In Python, extracting integer values from strings is a common task when processing text data. Python provides several approaches including the filter() method, regular expressions, and string manipulation techniques.

Using filter() and isdigit() Methods

The filter() method creates a new iterator by filtering elements based on a condition. When combined with isdigit(), it extracts only the digit characters from a string ?

text = "There are 20 teams competing in the Premier League"

print("The given string is:")
print(text)

# Extract digits and join them
digits = ''.join(filter(str.isdigit, text))
if digits:
    print("The number present in the string is:")
    print(int(digits))
else:
    print("No digits found")

The given string is:
There are 20 teams competing in the Premier League
The number present in the string is:
20

Using Regular Expressions

Regular expressions provide powerful pattern matching capabilities. The \d+ pattern matches one or more consecutive digits, making it ideal for extracting multiple numbers from text ?

import re

text = "There are 21 oranges, 13 apples and 18 bananas in the basket"

print("The given string is:")
print(text)

# Find all numbers in the string
numbers = re.findall(r'\d+', text)
integer_list = list(map(int, numbers))

print("The numbers present in the string are:")
print(integer_list)

The given string is:
There are 21 oranges, 13 apples and 18 bananas in the basket
The numbers present in the string are:
[21, 13, 18]

Using split() and isdigit() Methods

This approach splits the string into words and checks each word to see if it contains only digits ?

text = "There are 21 oranges, 13 apples and 18 bananas in the basket"

print("The given string is:")
print(text)

# Split string and filter digits
numbers = []
for word in text.split():
    # Remove punctuation and check if remaining is digit
    clean_word = ''.join(char for char in word if char.isdigit())
    if clean_word:
        numbers.append(int(clean_word))

print("The numbers present in the string are:")
print(numbers)

The given string is:
There are 21 oranges, 13 apples and 18 bananas in the basket
The numbers present in the string are:
[21, 13, 18]

Comparison of Methods

Conclusion

Use regular expressions for the most flexible integer extraction from strings. The filter() method works best for single continuous numbers, while split() is effective for word-separated values.