CODEWITHSUNDEEP
pythonstringlistsorting
user7074495
user7074495

Reputation:

Sorting list of strings alphabetically ignoring vowels python

If I have a list of strings, how would I sort it alphabetically by ignoring vowels. For example, ['alpha', 'beta'] would sort to ['beta', 'alpha'], because 'bt' is alphabetically before 'lph'. I've tried it a bit using lambda functions and stuff, but I am a bit stuck, any help would be appreciated.

Upvotes: 2

Views: 989

Answers (3)

Moinuddin Quadri
Moinuddin Quadri

Reputation: 48090

In Python 2.x, you may use string.translate() within lambda to remove the vowels from the string as:

>>> my_list = ['alpha', 'beta', 'gamma', 'theta']
>>> vowels = 'aeiouAEIOU' # string of 'vowel'

>>> sorted(my_list, key=lambda s: s.translate(None, vowels))
['beta', 'gamma', 'alpha', 'theta']

But in Python 3.x, you need to firstly convert the string to byte in order to access the translate function. for example:

sorted(my_list, key=lambda s: s.encode.translate(None, b'aeiouAEIOU')
# Note: This will work on Python 2.x as well, but encoding is not required there

As an alternative, you also use the below lambda expression within the sorted which will work fine on both Python 2.x and 3.x:

sorted(my_list, key=lambda s: ''.join(c for c in s if c not in vowels))

Upvotes: 2

John La Rooy
John La Rooy

Reputation: 304375

It's a good idea to use a named function here. There are two benefits - you can use a descriptive name, and you've got a function that can be unit tested.

def remove_vowels_from_string(s):
    return s.translate(None, 'aeiouAEIOU')

new_list = sorted(my_list, key=remove_vowels_from_string)

For Python3, you can use this version

def remove_vowels_from_string(s):
    return translate(dict.fromkeys(map(ord, 'aeiouAEIOU')))

new_list = sorted(my_list, key=remove_vowels_from_string)

Upvotes: 1

stamaimer
stamaimer

Reputation: 6475

You can use a lambda function in the key parameter of sorted function.

In [14]: l = ['alpha', 'beta']
In [15]: v = {'a', 'e', 'i', 'o', 'u'}
In [16]: sorted(l, key=lambda item: [char for char in item if char.lower() not in v])
Out[16]: ['beta', 'alpha']

Upvotes: 3

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