How to switch position of two items in a Python list?

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Track title: CC E Schuberts Piano Sonata D 784 in A

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Chapters
00:00 Question
00:49 Accepted answer (Score 476)
01:01 Answer 2 (Score 212)
01:22 Answer 3 (Score 18)
01:52 Answer 4 (Score 8)
02:09 Thank you

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Full question
https://stackoverflow.com/questions/2493...

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Content licensed under CC BY-SA
https://meta.stackexchange.com/help/lice...

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Tags
#python #list

#avk47

ACCEPTED ANSWER

Score 495

i = ['title', 'email', 'password2', 'password1', 'first_name', 
     'last_name', 'next', 'newsletter']
a, b = i.index('password2'), i.index('password1')
i[b], i[a] = i[a], i[b]

ANSWER 2

Score 223

The simple Python swap looks like this:

foo[i], foo[j] = foo[j], foo[i]

Now all you need to do is figure what i is, and that can easily be done with index:

i = foo.index("password2")

ANSWER 3

Score 19

Given your specs, I'd use slice-assignment:

>>> L = ['title', 'email', 'password2', 'password1', 'first_name', 'last_name', 'next', 'newsletter']
>>> i = L.index('password2')
>>> L[i:i+2] = L[i+1:i-1:-1]
>>> L
['title', 'email', 'password1', 'password2', 'first_name', 'last_name', 'next', 'newsletter']

The right-hand side of the slice assignment is a "reversed slice" and could also be spelled:

L[i:i+2] = reversed(L[i:i+2])

if you find that more readable, as many would.

ANSWER 4

Score 8

How can it ever be longer than

tmp = my_list[indexOfPwd2]
my_list[indexOfPwd2] = my_list[indexOfPwd2 + 1]
my_list[indexOfPwd2 + 1] = tmp

That's just a plain swap using temporary storage.