: splice keeps cutting off the third+ digit. Why? How do I fix this?

Question

So I have an assignment that I am working on in python, where I can only splice using the : splice method (i.e group= strg [:index]). For some reason splice refuses to see anything past 2 digits when its numbers. Words are fine but digits are being clipped.

here is my code:

import sys 

# set up for for loop
length = len(sys.argv)


for i in range(1, length):
   strg = sys.argv[i]
   #finds name
   index = strg.find(':')
   name  = strg[:index]
   strg  = strg[index+1:]
   
   index = strg.find(',')
   total  = 0
   count  = 0
   while (index != -1):
       group = strg[:index]
       try:
           num = int(group)
        
       except:
           break
       else:       
           print(num)    
           total = total+num
           count = count+1
           strg = strg[index+1:]
       
   print(count)
   avg = total/count
   print(name+", average:", avg)

input: Neda:90,80,70,90,50 John:80,100,30 Mary:20,100,90,80

my output:

90
80
70
90
50
5
Neda, average: 76.0
80
10
2
John, average: 45.0
20
10
2
Mary, average: 15.0

intended output:

90
80
70
90
50
5
Neda, average: 76.0
80
100
30
3
John, average: 70.0
20
100
90
80
4
Mary, average: 72.5

Answer 1

A simple fix would be to move

index = strg.find(',')

into the inner loop and test its result to determine how to extract the next number:

import sys

for string in sys.argv[1:]:
    # find name
    index = string.find(':')
    name = string[:index]

    total = 0
    count = 0

    while index != -1:
        string = string[index+1:]

        index = string.find(',')

        if index == -1:
            text = string[index+1:]
        else:
            text = string[:index]

        try:
            number = int(text)
        except ValueError:
            break

        print(number)
        total = total + number
        count = count + 1

    print(count)
    avg = total/count
    print(name + ", average:", avg)