CODEWITHSUNDEEP
pythonarrayspython-3.xfunction
H Morrow
H Morrow

Reputation: 13

How to append items from one list to another in Python 3

I'm trying to program the 'Card Trick' practice program for GCSE Computer Science but I'm stuck on one function.

I have an array which contains 3 other arrays, and I want to take the items within the 3 arrays and move them into another list.

This is the code which I have and I'm not sure why it doesn't work:

def remake_list(old_piles,mid_pile) :
    print(old_piles)
    newlist = []
    if mid_pile == 1 :
        newlist.extend(old_piles[1])
        newlist.extend(old_piles[0])
        newlist.extend(old_piles[2])
    if mid_pile == 2 :
        newlist.extend(old_piles[0])
        newlist.extend(old_piles[1])
        newlist.extend(old_piles[2])
    if mid_pile == 3 :
        newlist.extend(old_piles[0])
        newlist.extend(old_piles[2])
        newlist.extend(old_piles[1])
    return newlist

If old_piles was to be :

[['S8', 'S6', 'H3', 'DK', 'D8', 'C8', 'D2'], ['SQ', ',H2', 'S2', 'S4', 'D7', 'CK', 'SJ'], ['CA', 'D3', 'DQ', 'DJ', 'C9', 'H10', 'S7']]

And mid_pile was 3, how would I get this to work??

Upvotes: 1

Views: 94

Answers (2)

Djaouad
Djaouad

Reputation: 22776

You can just use list addition :

def remake_list(old_piles,mid_pile) :
    print(old_piles)
    newlist = []
    if mid_pile == 1 :
        newlist = old_piles[1] + old_piles[0] + old_piles[2]
    if mid_pile == 2 :
        newlist = old_piles[0] + old_piles[1] + old_piles[2]
    if mid_pile == 3 :
        newlist = old_piles[0] + old_piles[2] + old_piles[1]
    return newlist

Upvotes: 1

AlanK
AlanK

Reputation: 9833

Use itertools.chain

import itertools

deck = [['S8', 'S6', 'H3', 'DK', 'D8', 'C8', 'D2'], ['SQ', ',H2', 'S2', 'S4', 'D7', 'CK', 'SJ'], ['CA', 'D3', 'DQ', 'DJ', 'C9', 'H10', 'S7']]

print(list(itertools.chain(*deck)))
>> ['S8', 'S6', 'H3', 'DK', 'D8', 'C8', 'D2', 'SQ', ',H2', 'S2', 'S4', 'D7', 'CK', 'SJ', 'CA', 'D3', 'DQ', 'DJ', 'C9', 'H10', 'S7']

Upvotes: 1

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