Python program to Count Uppercase, Lowercase, special character and numeric values using Regex

Prerequisites: Regular Expression in Python

Given a string. The task is to count the number of Uppercase, Lowercase, special character and numeric values present in the string using Regular expression in Python.

Examples:

Input : 
"ThisIsGeeksforGeeks!, 123" 
Output :
No. of uppercase characters = 4
No. of lowercase characters = 15
No. of numerical characters = 3
No. of special characters = 2

Python program to Count Uppercase, Lowercase, special character and numeric values using Regex

Example 1:

The re.findall(pattern, string, flags=0) method can be used to find all non-overlapping matches of a pattern in the string. The return value is a list of strings.
Below is the implementation. 

Python3

import re


string = "ThisIsGeeksforGeeks !, 123"

# Creating separate lists using
# the re.findall() method.
uppercase_characters = re.findall(r"[A-Z]", string)
lowercase_characters = re.findall(r"[a-z]", string)
numerical_characters = re.findall(r"[0-9]", string)
special_characters = re.findall(r"[, .!?]", string)

print("The no. of uppercase characters is", len(uppercase_characters))
print("The no. of lowercase characters is", len(lowercase_characters))
print("The no. of numerical characters is", len(numerical_characters))
print("The no. of special characters is", len(special_characters))

Output:

The no. of uppercase characters is 4
The no. of lowercase characters is 15
The no. of numerical characters is 3
The no. of special characters is 4

Time complexity :  O(n)

Space Complexity : O(n)

Example 2:

Python3

import re

def count_characters(input_string):
    uppercase_count = len(re.findall(r'[A-Z]', input_string))
    lowercase_count = len(re.findall(r'[a-z]', input_string))
    special_char_count = len(re.findall(r'[!@#$%^&*()_+{}\[\]:;<>,.?\\/-]', input_string))
    numeric_count = len(re.findall(r'[0-9]', input_string))

    return uppercase_count, lowercase_count, special_char_count, numeric_count

test_string = "Hello World! 123"
uppercase, lowercase, special_chars, numeric = count_characters(test_string)

print("Uppercase count:", uppercase)
print("Lowercase count:", lowercase)
print("Special character count:", special_chars)
print("Numeric count:", numeric)

Output:

Uppercase count: 2
Lowercase count: 8
Special character count: 1
Numeric count: 3