python loop list index out of range

Question

i can't see it. why my loop is not well !? please try to help me :)

def sort_anagrams(list_of_strings):
    result = []
    for i in range(len(list_of_strings)):
        deleted_items = 0
        templist = []
        templist.append(list_of_strings[i])
        for j in range(i+1, len(list_of_strings) - deleted_items):
            print("*debug: i=", i, "j=", j, "len-list=", len(list_of_strings), "del-items=", deleted_items, "len-del=", len(list_of_strings) - deleted_items, "j-del = ", j-deleted_items)
            if sorted(list(list_of_strings[i])) == sorted(list(list_of_strings[j - deleted_items])):
                templist.append(list_of_strings[j - deleted_items])
                print("~joined!", templist)
                list_of_strings.remove(list_of_strings[j - deleted_items])
                deleted_items += 1
        result.append(templist)
    print(result)
    return result


list_of_words = ['deltas', 'retainers', 'desalt', 'pants', 'slated', 'generating', 'ternaries', 'smelters', 'termless', 'salted', 'staled', 'greatening', 'lasted', 'resmelts']
print(sort_anagrams(list_of_words))

#result:
#[['deltas', 'desalt', 'slated', 'salted', 'staled', 'lasted'], ['retainers', 'ternaries'], ['pants'], ['generating', 'greatening'], ['smelters', 'termless', 'resmelts']]

the code should return a new list of list's that contain the original worlds from list_of_words, grouped by anagrams (word's with the same letters)

Answer 1

for i in range(len(list_of_strings)):

Now you determined how many i you will have. It is determined at this moment because len(list_of_strings) gives you number, not reference to list lenght.

       list_of_strings.remove(list_of_strings[j - deleted_items])

Now you deleted something from the list, so at the end your list is shorter than starting len(list_of_strings). When i is bigger then current length of list python will raise IndexError: list index out of range.

Try to loop over elements of list with:

for element in my_list:
     do_something

Answer 2

Ok guy's, dynamic loop is just can't be crated with a for loop..

But? it working perfect with a while loop :) Thanks a lot!

def sort_anagrams(list_of_strings):
result = []
while list_of_strings:
    current_word = list_of_strings[0]
    temp_list = []
    rest_list = []
    for j in list_of_strings:
        if sorted(list(current_word)) == sorted(list(j)):
            temp_list.append(j)
        else:
            rest_list.append(j)
    result.append(temp_list)
    list_of_strings = rest_list
return result


list_of_words = ['deltas', 'retainers', 'desalt', 'pants', 'slated', 'generating', 'ternaries', 'smelters', 'termless', 'salted', 'staled', 'greatening', 'lasted', 'resmelts']
print(sort_anagrams(list_of_words))

#result:
print([['deltas', 'desalt', 'slated', 'salted', 'staled', 'lasted'], ['retainers', 'ternaries'], ['pants'], ['generating', 'greatening'], ['smelters', 'termless', 'resmelts']])