如何使用 Python 按字母数字顺序按值对字典进行排序？

Question

Im having a problem while sorting my dictionary with alphanumeric values. Each value has at least one letter in front (sometimes two) followed by some numbers. Example:

shoppingList = {'milk': 'W30', 'eggs': 'W29', 'tuna': 'W3', 'gum': 'CL24', 'beans': 'W6'}

When Im sorting it:

sorted_dict = sorted(shoppingList.items(), key = operator.itemgetter(1))

for i in sorted_dict:
    print(i)

Output:

('gum', 'CL24')
('eggs', 'W29')
('tuna', 'W3')
('milk', 'W30')
('beans', 'W6')

So it seems the sort is only using the first number it comes across. Is there a way to get the output as

('gum', 'CL24')
('tuna', 'W3')
('beans', 'W6')
('eggs', 'W29')
('milk', 'W30')

Thank you in advance.

Answer 1

Its sorting strings, not numbers, you need to parse the integer.

The one line approach would be ugly, so i'd be tempted to convert the given key below into a seperate function that can handle the splitting of the list

sorted(
    shoppingList.items(),
    key=lambda k: (
        ''.join(x for x in k[1] if not x.isdigit()),
        int(''.join(x for x in k[1] if x.isdigit())) 
    )
)

 [('gum', 'CL24'), ('tuna', 'W3'), ('beans', 'W6'), ('eggs', 'W29'), ('milk', 'W30')]

Answer 2

The module natsort will do this in the order you want.

from natsort import natsorted
from operator import itemgetter

D = natsorted(shoppingList.items(), key=itemgetter(1))

[('gum', 'CL24'), ('tuna', 'W3'), ('beans', 'W6'), ('eggs', 'W29'), ('milk', 'W30')]