Python sorting 2D array by the first element (not unique)
0
I have a very big 2D array where the second elements are not unique. Something like this:
list = [ ['text43','value43'],
['text23','value23'],
['text12','value12'],
['text43','different_val_43'],
['text12','another_value12'],
['text04','value04'],
['text43','anohter_value43'] ]
I would like to sort it by the first element but not in alphabetical order, just in the order of appearance of first element. Desired output:
list = [ ['text43','value43'],
['text43','different_val_43'],
['text43','anohter_value43'],
['text23','value23'],
['text12','value12'],
['text12','another_value12'],
['text04','value04'] ]
python arrays list sorting
asked Nov 13 '18 at 13:02
BirbalBirbal
587
add a comment |
0
I have a very big 2D array where the second elements are not unique. Something like this:
list = [ ['text43','value43'],
['text23','value23'],
['text12','value12'],
['text43','different_val_43'],
['text12','another_value12'],
['text04','value04'],
['text43','anohter_value43'] ]
I would like to sort it by the first element but not in alphabetical order, just in the order of appearance of first element. Desired output:
list = [ ['text43','value43'],
['text43','different_val_43'],
['text43','anohter_value43'],
['text23','value23'],
['text12','value12'],
['text12','another_value12'],
['text04','value04'] ]
python arrays list sorting
asked Nov 13 '18 at 13:02
BirbalBirbal
587
2
sorted(list1, key=lambda x: -int(x[0][-2:]))?
– Bear Brown
Nov 13 '18 at 13:07
Hello @Birbal, you'll need to add some code that you have already tried to make work. Have you tried anything?
– gkapellmann
Nov 13 '18 at 13:09
3
Do not uselistas the variable name of a python list. @BearBrown 's answer looks right.
– Charles Landau
Nov 13 '18 at 13:11
Thanks @CharlesLandau ...actually was just an example, I have not named itlist.
– Birbal
Nov 13 '18 at 13:51
add a comment |
0
0
0
I have a very big 2D array where the second elements are not unique. Something like this:
list = [ ['text43','value43'],
['text23','value23'],
['text12','value12'],
['text43','different_val_43'],
['text12','another_value12'],
['text04','value04'],
['text43','anohter_value43'] ]
I would like to sort it by the first element but not in alphabetical order, just in the order of appearance of first element. Desired output:
list = [ ['text43','value43'],
['text43','different_val_43'],
['text43','anohter_value43'],
['text23','value23'],
['text12','value12'],
['text12','another_value12'],
['text04','value04'] ]
python arrays list sorting
asked Nov 13 '18 at 13:02
BirbalBirbal
587
I have a very big 2D array where the second elements are not unique. Something like this:
list = [ ['text43','value43'],
['text23','value23'],
['text12','value12'],
['text43','different_val_43'],
['text12','another_value12'],
['text04','value04'],
['text43','anohter_value43'] ]
I would like to sort it by the first element but not in alphabetical order, just in the order of appearance of first element. Desired output:
list = [ ['text43','value43'],
['text43','different_val_43'],
['text43','anohter_value43'],
['text23','value23'],
['text12','value12'],
['text12','another_value12'],
['text04','value04'] ]
python arrays list sorting
python arrays list sorting
asked Nov 13 '18 at 13:02
BirbalBirbal
587
asked Nov 13 '18 at 13:02
BirbalBirbal
587
asked Nov 13 '18 at 13:02
BirbalBirbal
587
asked Nov 13 '18 at 13:02
BirbalBirbal
587
asked Nov 13 '18 at 13:02
BirbalBirbal
587
587
2
sorted(list1, key=lambda x: -int(x[0][-2:]))?
– Bear Brown
Nov 13 '18 at 13:07
Hello @Birbal, you'll need to add some code that you have already tried to make work. Have you tried anything?
– gkapellmann
Nov 13 '18 at 13:09
3
Do not uselistas the variable name of a python list. @BearBrown 's answer looks right.
– Charles Landau
Nov 13 '18 at 13:11
Thanks @CharlesLandau ...actually was just an example, I have not named itlist.
– Birbal
Nov 13 '18 at 13:51
add a comment |
2
sorted(list1, key=lambda x: -int(x[0][-2:]))?
– Bear Brown
Nov 13 '18 at 13:07
Hello @Birbal, you'll need to add some code that you have already tried to make work. Have you tried anything?
– gkapellmann
Nov 13 '18 at 13:09
3
Do not uselistas the variable name of a python list. @BearBrown 's answer looks right.
– Charles Landau
Nov 13 '18 at 13:11
Thanks @CharlesLandau ...actually was just an example, I have not named itlist.
– Birbal
Nov 13 '18 at 13:51
2
2
sorted(list1, key=lambda x: -int(x[0][-2:])) ?– Bear Brown
Nov 13 '18 at 13:07
sorted(list1, key=lambda x: -int(x[0][-2:])) ?– Bear Brown
Nov 13 '18 at 13:07
Hello @Birbal, you'll need to add some code that you have already tried to make work. Have you tried anything?
– gkapellmann
Nov 13 '18 at 13:09
Hello @Birbal, you'll need to add some code that you have already tried to make work. Have you tried anything?
– gkapellmann
Nov 13 '18 at 13:09
3
3
Do not use
list as the variable name of a python list. @BearBrown 's answer looks right.– Charles Landau
Nov 13 '18 at 13:11
Do not use
list as the variable name of a python list. @BearBrown 's answer looks right.– Charles Landau
Nov 13 '18 at 13:11
Thanks @CharlesLandau ...actually was just an example, I have not named it
list.– Birbal
Nov 13 '18 at 13:51
Thanks @CharlesLandau ...actually was just an example, I have not named it
list.– Birbal
Nov 13 '18 at 13:51
add a comment |
2 Answers
2
active
oldest
votes
3
You can use a custom sorting function that would return the index at which the first element of a sublist is first found, e.g.:
lst = [['text43','value43'],
['text23','value23'],
['text12','value12'],
['text43','different_val_43'],
['text12','another_value12'],
['text04','value04'],
['text43','anohter_value43']]
d =
for i, item in enumerate(lst):
if item[0] not in d:
d[item[0]] = i
lst.sort(key=lambda item: d[item[0]])
print(lst)
Output:
[['text43', 'value43'],
['text43', 'different_val_43'],
['text43', 'anohter_value43'],
['text23', 'value23'],
['text12', 'value12'],
['text12', 'another_value12'],
['text04', 'value04']]
answered Nov 13 '18 at 13:14
Eugene YarmashEugene Yarmash
83.6k22177259
add a comment |
0
Look if this helps. Using sorted()
lst = [ ['text43','value43'],
['text23','value23'],
['text12','value12'],
['text43','different_val_43'],
['text12','another_value12'],
['text04','value04'],
['text43','anohter_value43'] ]
sorted(lst, reverse=True)
Output:
[['text43', 'value43'],
['text43', 'different_val_43'],
['text43', 'anohter_value43'],
['text23', 'value23'],
['text12', 'value12'],
['text12', 'another_value12'],
['text04', 'value04']]
answered Nov 13 '18 at 14:11
Srce CdeSrce Cde
1,144511
add a comment |
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2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
3
You can use a custom sorting function that would return the index at which the first element of a sublist is first found, e.g.:
lst = [['text43','value43'],
['text23','value23'],
['text12','value12'],
['text43','different_val_43'],
['text12','another_value12'],
['text04','value04'],
['text43','anohter_value43']]
d =
for i, item in enumerate(lst):
if item[0] not in d:
d[item[0]] = i
lst.sort(key=lambda item: d[item[0]])
print(lst)
Output:
[['text43', 'value43'],
['text43', 'different_val_43'],
['text43', 'anohter_value43'],
['text23', 'value23'],
['text12', 'value12'],
['text12', 'another_value12'],
['text04', 'value04']]
answered Nov 13 '18 at 13:14
Eugene YarmashEugene Yarmash
83.6k22177259
add a comment |
3
You can use a custom sorting function that would return the index at which the first element of a sublist is first found, e.g.:
lst = [['text43','value43'],
['text23','value23'],
['text12','value12'],
['text43','different_val_43'],
['text12','another_value12'],
['text04','value04'],
['text43','anohter_value43']]
d =
for i, item in enumerate(lst):
if item[0] not in d:
d[item[0]] = i
lst.sort(key=lambda item: d[item[0]])
print(lst)
Output:
[['text43', 'value43'],
['text43', 'different_val_43'],
['text43', 'anohter_value43'],
['text23', 'value23'],
['text12', 'value12'],
['text12', 'another_value12'],
['text04', 'value04']]
answered Nov 13 '18 at 13:14
Eugene YarmashEugene Yarmash
83.6k22177259
add a comment |
3
3
3
You can use a custom sorting function that would return the index at which the first element of a sublist is first found, e.g.:
lst = [['text43','value43'],
['text23','value23'],
['text12','value12'],
['text43','different_val_43'],
['text12','another_value12'],
['text04','value04'],
['text43','anohter_value43']]
d =
for i, item in enumerate(lst):
if item[0] not in d:
d[item[0]] = i
lst.sort(key=lambda item: d[item[0]])
print(lst)
Output:
[['text43', 'value43'],
['text43', 'different_val_43'],
['text43', 'anohter_value43'],
['text23', 'value23'],
['text12', 'value12'],
['text12', 'another_value12'],
['text04', 'value04']]
answered Nov 13 '18 at 13:14
Eugene YarmashEugene Yarmash
83.6k22177259
You can use a custom sorting function that would return the index at which the first element of a sublist is first found, e.g.:
lst = [['text43','value43'],
['text23','value23'],
['text12','value12'],
['text43','different_val_43'],
['text12','another_value12'],
['text04','value04'],
['text43','anohter_value43']]
d =
for i, item in enumerate(lst):
if item[0] not in d:
d[item[0]] = i
lst.sort(key=lambda item: d[item[0]])
print(lst)
Output:
[['text43', 'value43'],
['text43', 'different_val_43'],
['text43', 'anohter_value43'],
['text23', 'value23'],
['text12', 'value12'],
['text12', 'another_value12'],
['text04', 'value04']]
answered Nov 13 '18 at 13:14
Eugene YarmashEugene Yarmash
83.6k22177259
edited Nov 13 '18 at 13:43
answered Nov 13 '18 at 13:14
Eugene YarmashEugene Yarmash
83.6k22177259
answered Nov 13 '18 at 13:14
Eugene YarmashEugene Yarmash
83.6k22177259
answered Nov 13 '18 at 13:14
Eugene YarmashEugene Yarmash
83.6k22177259
83.6k22177259
add a comment |
add a comment |
0
Look if this helps. Using sorted()
lst = [ ['text43','value43'],
['text23','value23'],
['text12','value12'],
['text43','different_val_43'],
['text12','another_value12'],
['text04','value04'],
['text43','anohter_value43'] ]
sorted(lst, reverse=True)
Output:
[['text43', 'value43'],
['text43', 'different_val_43'],
['text43', 'anohter_value43'],
['text23', 'value23'],
['text12', 'value12'],
['text12', 'another_value12'],
['text04', 'value04']]
answered Nov 13 '18 at 14:11
Srce CdeSrce Cde
1,144511
add a comment |
0
Look if this helps. Using sorted()
lst = [ ['text43','value43'],
['text23','value23'],
['text12','value12'],
['text43','different_val_43'],
['text12','another_value12'],
['text04','value04'],
['text43','anohter_value43'] ]
sorted(lst, reverse=True)
Output:
[['text43', 'value43'],
['text43', 'different_val_43'],
['text43', 'anohter_value43'],
['text23', 'value23'],
['text12', 'value12'],
['text12', 'another_value12'],
['text04', 'value04']]
answered Nov 13 '18 at 14:11
Srce CdeSrce Cde
1,144511
add a comment |
0
0
0
Look if this helps. Using sorted()
lst = [ ['text43','value43'],
['text23','value23'],
['text12','value12'],
['text43','different_val_43'],
['text12','another_value12'],
['text04','value04'],
['text43','anohter_value43'] ]
sorted(lst, reverse=True)
Output:
[['text43', 'value43'],
['text43', 'different_val_43'],
['text43', 'anohter_value43'],
['text23', 'value23'],
['text12', 'value12'],
['text12', 'another_value12'],
['text04', 'value04']]
answered Nov 13 '18 at 14:11
Srce CdeSrce Cde
1,144511
Look if this helps. Using sorted()
lst = [ ['text43','value43'],
['text23','value23'],
['text12','value12'],
['text43','different_val_43'],
['text12','another_value12'],
['text04','value04'],
['text43','anohter_value43'] ]
sorted(lst, reverse=True)
Output:
[['text43', 'value43'],
['text43', 'different_val_43'],
['text43', 'anohter_value43'],
['text23', 'value23'],
['text12', 'value12'],
['text12', 'another_value12'],
['text04', 'value04']]
answered Nov 13 '18 at 14:11
Srce CdeSrce Cde
1,144511
edited Nov 29 '18 at 18:10
answered Nov 13 '18 at 14:11
Srce CdeSrce Cde
1,144511
answered Nov 13 '18 at 14:11
Srce CdeSrce Cde
1,144511
answered Nov 13 '18 at 14:11
Srce CdeSrce Cde
1,144511
1,144511
add a comment |
add a comment |
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2
sorted(list1, key=lambda x: -int(x[0][-2:]))?– Bear Brown
Nov 13 '18 at 13:07
Hello @Birbal, you'll need to add some code that you have already tried to make work. Have you tried anything?
– gkapellmann
Nov 13 '18 at 13:09
3
Do not use
listas the variable name of a python list. @BearBrown 's answer looks right.– Charles Landau
Nov 13 '18 at 13:11
Thanks @CharlesLandau ...actually was just an example, I have not named it
list.– Birbal
Nov 13 '18 at 13:51