Python - 如何对字母和数值列表进行排序？

Question

Is there a fast way to sort this list :

list = ['J', 'E', 3, 7, 0]

in order to get this one (numeric first, and then alpha) in python? :

list = [0, 3, 7, 'E', 'J']

Answer 1

Since you're dealing with numbers (that, in this case, are <10) and strings, you can simplify your key and remove the lambda :

>>> sorted(lst, key=str)
[0, 3, 7, 'E', 'J']

Or, even better, use list.sort for an in-place sorting.

>>> lst.sort(key=str)
>>> lst
[0, 3, 7, 'E', 'J']

Each item will be sorted based on the ASCII value of the str -ified value.

Note that, if you're dealing with numbers >=10 (highly likely), then this solution will end up sorting the numbers lexicographically. To get around that, you will end up needing the lambda.

>>> lst.sort(key=lambda x: (isinstance(x, str), x)))

Which is @jpp's solution.

Answer 2

You can sort with a (Boolean, value) tuple:

L = ['J', 'E', 3, 7, 0]

res = sorted(L, key=lambda x: (isinstance(x, str), x))

# [0, 3, 7, 'E', 'J']

Answer 3

If you will use list.sort() on you list, you will get

TypeError: '<' not supported between instances of 'int' and 'str'

You have to convert all items in list into string type.

[str(i) for i in list]