Python program to calculate the number of all possible substrings of a string

Python code to count number of substrings of a string

def count_substr_by_formula(string):
    '''
    This function is used to calculate
    number of all possible substring of
    a string by a formula.
    '''

    substring = 0
    # length of the given string
    n = len(string)

    substring = n * (n + 1) // 2

    return substring

    # Time Complexity : O(1) {constant order}

def general_method(string):
    '''
    This function is used to calculate
    number of all possible substring of
    a string by using nested for loops.
    '''
    
    substring = 0
    n = len(string)
    # List to store all the calculated substrings
    substr = []

    for i in range(n):
        for j in range(i,n):
            substr.append(string[i:j])

    substring = len(substr)

    return substring

    # Time Complexity : O(n*n)

# Main Code
if __name__=='__main__':

    string = 'IncludeHelp'

    print('Total number of substring = %d' % count_substr_by_formula(string))
    print('Total number of substring = %d' % general_method(string))

Output

Total number of substring = 66
Total number of substring = 66