Sorting numbers correctly with a mixed list without sort()

Question

In my exercice I made a sort algorithm. I have a text file and put it in a list.

text = file.read().split()

like this. So means my list contains numbers and letters in form of a string.

def insertion_sort(self, arr):
    for i in range(1, len(arr)):
        val = arr[i] #value
        pos = i #position
        while pos > 0 and val < arr[pos-1] :
            arr[pos] = arr[pos-1] #Move elements ahead
            pos -= 1
        arr[pos] = val #sort the value to the correct position

The algorithm now sorts the numbers incorrectly of course. What would be the best solution to sort it correctly?

Edit: My string for example: ["1", "e", "2", "d", "10"] - Output that I get: 1,10,2,d,e - Output that I want: 1,2,10,d,e

Answer 1

With minimum changes from your code, you can extract "numbers" from your list and use exactly the same algorithm. For example:

def insertion_sort(arr):
    arr_num = []
    arr_str = []
    # if the value is a number, then add it to arr_num, else to arr_str
    for val in arr:
        try:
            arr_num.append(float(val))
        except:
            arr_str.append(val)
    
    #your algorithm applied to arr_num
    for i in range(1, len(arr_num)):
        val = arr_num[i] #value
        pos = i #position
        while pos > 0 and val < arr_num[pos-1] :
            arr_num[pos] = arr_num[pos-1] #Move elements ahead
            pos -= 1
        arr_num[pos] = val #sort the value to the correct position

    #To convert back to string if needed
    for i,val in enumerate(arr_num):
        arr_num[i] = str(val)

    #To concatenate  list of numbers and string if needed
    arr = arr_num+arr_str
    return arr

And I get:

a = ["7", "c", "b", "10", "a"]

insertion_sort(a)
Out[57]: ['7.0', '10.0', 'c', 'b', 'a']