Question

Im looking to create a program in python that asks the user to enter a list of numbers in [] format.

It then must count and display how many of those numbers in the list are between 1 and 10, 10 and 20,
20 and 30 ect.

Here is what i have so far.

my_num = [int(i) for i in raw_input("Enter numbers... ").split(",")]

the_list = eval(my_num)

number = 0

if 1<= my_num and my_num <=10:
    number = number + 1

Answer 1

import itertools

numbers = sorted(map(int, raw_input().split(",")))
for k, g in itertools.groupby(numbers, lambda x: x // 10):
    print k, list(g)

This will give you groups of numbers, and you can count the instances in the group with calls to len(). For instance, replace

    # print k, list(g)
    print k, len(list(g))

The important thing is to sort the numbers first.

With this as input:

1, 5, 6, 89, 43, 43, 25, 76, 12, 32, 23, 25, 27, 13, 5, 7

0 [1, 5, 5, 6, 7]
1 [12, 13]
2 [23, 25, 25, 27]
3 [32]
4 [43, 43]
7 [76]
8 [89]

Or the output with the len call instead:

0 5
1 2
2 4
3 1
4 2
7 1
8 1

Which could then be formatted like this:

print "%d - %d: %d" % (k * 10 + 1, (k + 1) * 10, len(list(g))

Yielding:

 1 - 10: 5
11 - 20: 2
21 - 30: 4
31 - 40: 1
41 - 50: 2
71 - 80: 1
81 - 90: 1