How to sort dependent lists

Question

I have 3 lists A B & C. all are of the same length. list A needs to be sorted but list B and C also needs to change its orders to reflect the sorting to maintain the value relationships between the three lists. I am unsure how to achieve this with python.

Answer 1

# Convert your three lists in a unique list of dicts/objects, then sort this list by key:

list1 = [ 7, 2, 5 ]
list2 = [ 'b', 'a', 'c' ]
list3 = [ 42, 64, 32 ]
ulist = [ ]
for i in range(len(list1)):
ulist.append({ 'list1' : list1[i], 'list2' : list2[i], 'list3' : list3[i] })
ulist.sort(key=lambda v: v['list2'])

# if necessary, you can convert back the unique list to three separated ones:

list1 = [ ]
list2 = [ ]
list3 = [ ]
for index in range(len(ulist)):
list1.append(ulist[index]['list1'])
list2.append(ulist[index]['list2'])
list3.append(ulist[index]['list3'])

# you could use list comprehension also, but for long list this will be less efficient, as you need iterate 3 times over the unique list instead of only once:

list1 = [ value['list1'] for value in ulist ]
list2 = [ value['list2'] for value in ulist ]
list3 = [ value['list3'] for value in ulist ]

Answer 2

i did not use a list of dictionaries since the items in the main sorting list is non unique. I used a list of lists and i was able to achieve sorting as I desired it thank you for pointing me in the right direction.