返回字典时，python的行为类似于JavaScript吗？

Question

I was wondering:

def get_empty_cell():
    return {'p': [[], []], 'h': {}, 'b': []}

def create_new_board(old_board):
    height = len(old_board) + 4
    width = len(old_board[0]) + 4
    self.board = [None] * height
    for i in range(0, height):
        self.board[i] = [None] * width
        for j in range(0, width):
            # (!) deepcopy() 
            self.board[i][j] = copy.deepcopy(self.get_empty_cell())

I'm using deepcopy because I've had many situations where different variables access the same content. But when Python returns "new" dictionaries like in my code, do I need to use copy.deepcopy if I want different cells or is it like JavaScript?

(and off topic: I'm sure my code could be optimized "the Python way"...)

Answer 1

get_empty_cell() returns a new dictionary from a literal each time. There's no need to copy it again.

Answer 2

As in the other answer, you don't need to make a copy because get_empty_cell() returns a new dict each time you call it.

And yes! you can optimize your code like this:

self.board = [[self.get_empty_cell() for j in range(width)] for i in range(height)]