Python – Extract Percentages from String

When extracting percentages from a string, we use Python's regular expressions module (re) with the findall() method to locate and extract percentage values.

Basic Example with Actual Percentages

Let's extract percentage values from a string containing actual numeric percentages ?

import re

my_string = 'The success rate is 85% and failure rate is 15% with 5% margin error'

print("Original string:")
print(my_string)

# Extract percentages using regex
percentages = re.findall(r'\d+%', my_string)

print("\nExtracted percentages:")
print(percentages)

Original string:
The success rate is 85% and failure rate is 15% with 5% margin error

Extracted percentages:
['85%', '15%', '5%']

Extract Decimal Percentages

To handle decimal percentages like 12.5%, we modify the regex pattern ?

import re

text = 'Growth was 12.5% last year and 8.75% this quarter'

# Pattern for decimal percentages
decimal_percentages = re.findall(r'\d+\.?\d*%', text)

print("Text:", text)
print("Decimal percentages:", decimal_percentages)

Text: Growth was 12.5% last year and 8.75% this quarter
Decimal percentages: ['12.5%', '8.75%']

Extract Only Numeric Values

To get just the numeric values without the % symbol ?

import re

data = 'Scores: 92%, 78%, 85.5%, 91%'

# Extract numbers before % symbol
numbers = re.findall(r'(\d+\.?\d*)%', data)

print("Original data:", data)
print("Numeric values:", numbers)

# Convert to float for calculations
numeric_values = [float(num) for num in numbers]
print("As floats:", numeric_values)
print("Average:", sum(numeric_values) / len(numeric_values))

Original data: Scores: 92%, 78%, 85.5%, 91%
Numeric values: ['92', '78', '85.5', '91']
As floats: [92.0, 78.0, 85.5, 91.0]
Average: 86.625

Regex Pattern Breakdown

Conclusion

Use re.findall() with appropriate regex patterns to extract percentages from strings. The pattern \d+\.?\d*% handles both integer and decimal percentages effectively.