Python list 函数生成 1 个额外的列表

Question

def randomly_pokemon_select_function():
    from random import randint
    import linecache

open_pokedex=open("pokedex.txt","r")

p1_p1=list()
p1_p2=list()
p1_p3=list()
p2_p1=list()
p2_p2=list()
p2_p3=list()
player1_pokemons=list()
player2_pokemons=list()
pokemon_selection=(randint(1,40))
p1_p1.append(linecache.getline("pokedex.txt", pokemon_selection).split())
pokemon_selection=(randint(1,40))
p1_p2.append(linecache.getline("pokedex.txt", pokemon_selection).split())
pokemon_selection=(randint(1,40))
p1_p3.append(linecache.getline("pokedex.txt", pokemon_selection).split())
pokemon_selection=(randint(1,40))
p2_p1.append(linecache.getline("pokedex.txt", pokemon_selection).split())
pokemon_selection=(randint(1,40))
p2_p2.append(linecache.getline("pokedex.txt", pokemon_selection).split())
pokemon_selection=(randint(1,40))
p2_p3.append(linecache.getline("pokedex.txt", pokemon_selection).split())
player1_pokemons.append(p1_p1+p1_p2+p1_p3)
player2_pokemons.append(p2_p1+p2_p2+p2_p3)
open_pokedex.close()
print player1_pokemons
print player2_pokemons
return player1_pokemons,player2_pokemons

这段代码运行良好，但它似乎生成了一个额外的列表。输出如下所示：

[[['Geodude'，'40'，'80'，'摇滚'，'格斗']，
['Raichu', '60', '90', '电动', '普通'],
['Golem', '80', '120', 'Rock', 'Fighting']]]

强括号是额外的，我找不到哪一行生成了额外的列表。

Answer 1

您为这些构建了 3 个列表，p1_p1,p1_p2andp1_p3; each is a list containing another list, because you append the result ofstr.split()`。

每个看起来像这样：

[[datum, datum, datum, datum, datum]]

然后，您使用+ 将这些列表连接在一起，并将它们附加到player1_pokemons，这已经是一个列表对象。与其追加，只需将其设为您的列表：

player1_pokemons = p1_p1 + p1_p2 + p1_p3

或者不附加到单独的p1_p1、p1_p2 等列表，而是直接附加到player1_pokemons。您可以循环执行此操作：

player1_pokemons = [
    linecache.getline("pokedex.txt", randint(1, 40)).split()
    for _ in range(3)]
player2_pokemons = [
    linecache.getline("pokedex.txt", randint(1, 40)).split()
    for _ in range(3)]

注意linecache模块已经为你打开并读取了文件，你不需要自己打开文件。

Answer 2

在 append 方法中添加列表时，您正在创建列表列表，然后将其附加到列表中。