Question

I would like to move more than one item from one list to another.

list1 = ['2D','  ','  ','  ','  ','  ','  ','  ','  ']
list2 = ['XX','XX','5D','4S','3D','  ','  ','  ','  ']
list3 = ['XX','XX','XX','8C','7H','6C','  ','  ','  ']

In the code above ' ' is a double space

I would like to be able to move '5D','4S','3D' from list2 onto '8C','7H','6C' in list3.

I’ve tried the code below but it doesn’t work.

list1 = ['2D','  ','  ','  ','  ','  ','  ','  ','  ']
list2 = ['XX','XX','5D','4S','3D','  ','  ','  ','  ']
list3 = ['XX','XX','XX','8C','7H','6C','  ','  ','  ']


items_to_be_moved = list2[list2.index('XX')+2 : list2.index('  ')]

list3[list3.index('  ')] = items_to_be_moved
del list2[list2.index('XX')+2 : list2.index('  ')]

print('list2',list2)
print('list3',list3)

and this returns

list2 ['XX', 'XX', '  ', '  ', '  ', '  ']
list3 ['XX', 'XX', 'XX', '8C', '7H', '6C', ['5D', '4S', '3D'], '  ', '  ']

However, i dont want to use list2.index('XX')+2, i would like to use a code that gives the last index of 'XX' just like list2.index(' ') gives the first index of ' '.

Also, i dont want the moved items to be in a separate list of their own within another list.
For example: instead of returning

"list3 ['XX', 'XX', 'XX', '8C', '7H', '6C', ['5D', '4S', '3D'], '  ', '  ']"

the list

"list3 ['XX', 'XX', 'XX', '8C', '7H', '6C','5D', '4S', '3D', '  ', '  ']"

should be returned.

Answer 1

To replace the correct items, use slice assignment.

list1 = ['2D','  ','  ','  ','  ','  ','  ','  ','  ']
list2 = ['XX','XX','5D','4S','3D','  ','  ','  ','  ']
list3 = ['XX','XX','XX','8C','7H','6C','  ','  ','  ']

list3[3:6] = list2[2:5]

print list3
# ['XX', 'XX', 'XX', '5D', '4S', '3D', '  ', '  ', '  ']

If you want to start from after the final consecutive 'XX', you can use:

from itertools import takewhile
i = sum(1 for _ in takewhile(lambda elem: elem == 'XX', list3))

list3[i:i+3] = list2[i-1:i+2]

to find the index of the last one.