Issue sorting tuples in python3

Question

Below is my code and i am trying to sort the tuple with respect to 2nd element.

list = ["abc14_90","abc44_88","abc14_89"]
listLength = len(list)
for i in range(0,listLength):
    tempList = list[i].split('_')
    tempList1 = tempList[0].split('c')
    if(i==0):
        tupleNumber = [(list[i], int(tempList1[1]),int(tempList[1]))]
    else:
        tupleNumber = tupleNumber + [(list[i], int(tempList1[1]),int(tempList[1]))]

print (tupleNumber)

sorted(tupleNumber, key=lambda x: x[2])

print (tupleNumber)

Expected Output:

[ ('abc44_88', 44, 88), ('abc14_89', 14, 89),('abc14_90', 14, 90),]

Output Observed:

[('abc14_90', 14, 90), ('abc44_88', 44, 88), ('abc14_89', 14, 89)]

Basically the sort seems to have no effect.

Why not just `list_.sort(key=lambda x: re.search('(\d+)$', x).group(1)) ` — cs95, Sep 03 '17 at 00:18

score 0 · Answer 1 · answered Sep 03 '17 at 00:12

0

sorted() doesn't sort in place but it returns a sorted list, so you need to reassign the list to tupleNumber as the following:

print (tupleNumber)

tupleNumber = sorted(tupleNumber, key=lambda x: x[2])

print (tupleNumber)

answered Sep 03 '17 at 00:12

Mohd

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I think he meant second element from the initial value which is the third element in the tuple ie: `abc44_88` -> `('abc44_88', 44, 88)` – Mohd Sep 03 '17 at 00:13
might also want to point out the `.sort()` method of lists – anthony sottile Sep 03 '17 at 00:14
@MoeA Hmm, I guess so. Perhaps OP should clarify. – Christian Dean Sep 03 '17 at 00:14
Thanks. I thought it sorts in place. Also, i meant second element from initial value. – moooni moon Sep 03 '17 at 00:15
@mooonimoon as @AnthonySottile mentioned, you can use `tupleNumber.sort()` which will sort in place – Mohd Sep 03 '17 at 00:16
Thanks @AnthonySottile and MoeA will look into that method. – moooni moon Sep 03 '17 at 00:20

Ajax1234 · Answer 2 · 2017-09-03T01:00:08.863

-1

You can try this:

import re
import itertools
l = ["abc14_90","abc44_88","abc14_89"]
new_l = [tuple(itertools.chain.from_iterable([[i], map(int, re.findall("\d+", i))])) for i in sorted(l, key=lambda x: int(x[-2:]))]

Output:

[('abc44_88', 44, 88), ('abc14_89', 14, 89), ('abc14_90', 14, 90)]

edited Sep 03 '17 at 01:00

answered Sep 03 '17 at 00:53

Ajax1234

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Issue sorting tuples in python3

2 Answers2