Functional Conway's Game of Life

Game of Life

import copy
def next_state(current_state, nr_neighbors):
    if (current_state and (nr_neighbors < 2 or nr_neighbors > 3)) or\
        (not current_state and nr_neighbors == 3):
        return not current_state
    return current_state

def are_neighbors(cell1,cell2):
    return abs(cell1[0] - cell2[0]) <= 1 and abs(cell1[1] - cell2[1]) <= 1 \
            and cell1 != cell2

def nr_alive_neighbors(alive_cells,cell):
    if not alive_cells:
        return 0
    return are_neighbors(cell,alive_cells[0]) + nr_alive_neighbors(alive_cells[1:],cell)

def dead_neighbors(alive_cells,cell):
    return {(i,j) for i in range(cell[0]-1,cell[0]+2) for j in range(cell[1]-1,cell[1]+2)
                if are_neighbors(cell,(i,j)) and (i,j) not in alive_cells}

def tick(cells):
    deadNeighbors = set()
    cellCopy = [cell for cell in cells if  next_state(True,nr_alive_neighbors(cells,cell))]
    deadNeighbors = {dead_cell  for cell in cells for dead_cell in dead_neighbors(cells,cell)}
    cellCopy.extend(cell for cell in deadNeighbors if next_state(False,nr_alive_neighbors(cells,cell)))
    return cellCopy