CODEWITHSUNDEEP
pythonlistsorting
Sandy
Sandy

Reputation: 359

How to sort multiple strings inside list alphabetically ascending in Python

I'd like to write a function which can return the sorted strings inside a list by alphabetically ascending. Like it should turn

["banana apple", "cat elephant dog"]

into

["apple banana", "cat dog elephant"].

I tried:

def apply_to_list(string_list):
   new = []
   for i in [0,len(string_list)-1]:
    data = sorted(string_list[i])
    new = data.append
    print(new)
    return new

It turned out to be wrong. I know how to sort if the list is simple, I can do:

def sort_words(string):
    words = [word.lower() for word in string.split()]
    words.sort()
    for word in words:
    print(word)
    return

However, when it comes to several strings inside each of the attribute of a list, my approach failed. Can anyone help?

Upvotes: 0

Views: 904

Answers (3)

vaeVictis
vaeVictis

Reputation: 492

Since you want to sort all the strings in the list, you could use a list comprehension over the items inside your list.

For any item, which is the string you want to sort, split the item and obtain a list of its words. Then use sorted to obtain a sorted version of this list. Finally use join with " " to rebuild a string with all its substrings sorted:

foo = ["banana apple", "cat elephant dog"] 

def apply_to_list(myList):
    return [ ' '.join(sorted(item.split())) for item in myList ]
    
print(apply_to_list(foo))

Which outputs:

['apple banana', 'cat dog elephant']

This being said, your function:

def apply_to_list(string_list):
   new = []
   for i in [0,len(string_list)-1]:
    data = sorted(string_list[i])
    new = data.append
    print(new)
    return new

has some issues.

  1. The indentation is not uniform.

  2. string_list is an iterable. You should iterate directly over it, without using indexing.

  3. string_list[i] is a string. You should apply split before sorted. For example, if you have my_string="banana apple" and apply sorted directly, you obtain

    [' ', 'a', 'a', 'a', 'a', 'b', 'e', 'l', 'n', 'n', 'p', 'p']

  4. Considering the previous issue, the way you use append is not correct. append is a list method and it's called this way

    list_to_which_append.append(element_to_append)

Moreover, you don't call the method, so in your code, new is <built-in method append of list object at 0x7fba704d4b80> (the address is indicative and may vary).

If you want to correct that function, the code is:

def apply_to_list(string_list):
    new = []
    for item in string_list:
        data = sorted(item.split())
        new.append(' '.join(data))
    return new

Upvotes: -1

AJITH
AJITH

Reputation: 1175

words = ["banana apple", "cat elephant dog"] 

s = [' '.join(sorted(word.split(' '))) for word in words]
print(s)

#['apple banana', 'cat dog elephant']

Upvotes: 1

user7864386
user7864386

Reputation:

For each string, you can use str.split to get individual words + sorted to sort the words + join to join back the words into a single string in a list comprehension:

[' '.join(sorted(x.split())) for x in lst]

Output:

['apple banana', 'cat dog elephant']

Upvotes: 2

Related Questions