在python中混合列表

Question

from itertools import product

x_coord = ['a','b','c','d','e']
y_coord = ['1', '2', '3', '4', '5']

board = []
index = 0

for item in itertools.product(x_coord, y_coord): 

    board += item

    for elements in board:

        board[index] = board[index] + board[index +1]
        board.remove(board[index +1])
        index += 1


print board

---

Hello. Let me explain what I want to do with that:

I have two lists( x_coord and y_coord ) and I want to mix them like that:

board = ['a1', 'a2', ..., 'e1', 'e2', ...]

But I get the IndexError: list index out of range error instead of that.

How should I proceed?

OBS.:If there's any type of error in my english, please tell me. I'm learning english as well as code.

Answer 1

You can try like that,

>>> x_coord = ['a','b','c','d','e']
>>> y_coord = ['1', '2', '3', '4', '5']
>>> [item + item2 for item2 in y_coord for item in x_coord]
['a1', 'b1', 'c1', 'd1', 'e1', 'a2', 'b2', 'c2', 'd2', 'e2', 'a3', 'b3', 'c3', 'd3', 'e3', 'a4', 'b4', 'c4', 'd4', 'e4', 'a5', 'b5', 'c5', 'd5', 'e5']

Sorted results:

 >>> sorted([item + item2 for item2 in y_coord for item in x_coord])
['a1', 'a2', 'a3', 'a4', 'a5', 'b1', 'b2', 'b3', 'b4', 'b5', 'c1', 'c2', 'c3', 'c4', 'c5', 'd1', 'd2', 'd3', 'd4', 'd5', 'e1', 'e2', 'e3', 'e4', 'e5']

Answer 2

t = [a + b for a,b in itertools.product(x_coord,y_coord)]
print t % prints what you want

Normally itertools.product(x_coord,y_coord) will print the following: [('a', '1'), ('a', '2'), ('a', '3'), ('a', '4'), ('a', '5'), ('b', '1'), ('b', '2'), ('b', '3'), ('b', '4'), ('b', '5'), ('c', '1'), ('c', '2'), ('c', '3'), ('c', '4'), ('c', '5'), ('d', '1'), ('d', '2'), ('d', '3'), ('d', '4'), ('d', '5'), ('e', '1'), ('e', '2'), ('e', '3'), ('e', '4'), ('e', '5')]

As you can see it's already in order because itertools.product will multiply a by each index in y_coord before moving x_coord to b , etc. etc.

By using list comprehension we can combine the two indices using a+b for each pair in the output, resulting in this:
['a1', 'a2', 'a3', 'a4', 'a5', 'b1', 'b2', 'b3', 'b4', 'b5', 'c1', 'c2', 'c3', 'c4', 'c5', 'd1', 'd2', 'd3', 'd4', 'd5', 'e1', 'e2', 'e3', 'e4', 'e5']

Answer 3

combined = map(lambda x: ''.join(x), product(x_coord, y_coord))

Answer 4

coord = map(lambda x,y: x+y, x_coord, y_coord)   
print(coord)  

Answer 5

x_coord = ['a','b','c','d','e']
y_coord = ['1', '2', '3', '4', '5']
a=[]
for i in range(len(x_coord)):
    for j in range(len(y_coord)):
        a.append(x_coord[i].join(" "+ y_coord[j]))
b=[]
for item in a:
    b.append(item.replace(" ",""))
print b