NumberToWords.py

def convert_to_words(num):
     
    l = len(num); 
    if (l == 0):
        print("empty string");
        return;
 
    if (l > 4):
        print("Length more than 4 is not supported");
        return;
 
    single_digits = ["zero", "one", "two", "three", 
                     "four", "five", "six", "seven", 
                     "eight", "nine"];
 
    two_digits = ["", "ten", "eleven", "twelve", 
                  "thirteen", "fourteen", "fifteen", 
                  "sixteen", "seventeen", "eighteen",
                  "nineteen"];
 
    tens_multiple = ["", "", "twenty", "thirty", "forty",
                     "fifty", "sixty", "seventy", "eighty", 
                     "ninety"];
 
    tens_power = ["hundred", "thousand"];
 
    # Used for debugging purpose only 
    print(num, ":", end = " ");

    if (l == 1): 
        print(single_digits[ord(num[0]) - '0']);
        return;

    x = 0;
    while (x < len(num)): 
         
        if (l >= 3):
            if (ord(num[x]) - 48 != 0):
                print(single_digits[ord(num[x]) - 48], 
                                           end = " ");
                print(tens_power[l - 3], end = " "); 
                 
            l -= 1;
             
        else:

            if (ord(num[x]) - 48 == 1): 
                sum = (ord(num[x]) - 48 +
                       ord(num[x+1]) - 48);
                print(two_digits[sum]);
                return;
 
            elif (ord(num[x]) - 48 == 2 and
                  ord(num[x + 1]) - 48 == 0):
                print("twenty");
                return;
                 

            else:
                i = ord(num[x]) - 48;
                if(i > 0):
                    print(tens_multiple[i], end = " ");
                else:
                    print("", end = "");
                x += 1;
                if(ord(num[x]) - 48 != 0):
                    print(single_digits[ord(num[x]) - 48]);
        x += 1;
 
# Driver Code
convert_to_words("9923");
convert_to_words("523");
convert_to_words("89");
convert_to_words("8989");