下面是一个字典类的Python代码，它可以在O(1)时间内返回随机键。(为了可读性，我在代码中包含了myypy类型):

from typing import TypeVar, Generic, Dict, List
import random

K = TypeVar('K')
V = TypeVar('V')
class IndexableDict(Generic[K, V]):
    def __init__(self) -> None:
        self.keys: List[K] = []
        self.vals: List[V] = []
        self.dict: Dict[K, int] = {}

    def __getitem__(self, key: K) -> V:
        return self.vals[self.dict[key]]

    def __setitem__(self, key: K, val: V) -> None:
        if key in self.dict:
            index = self.dict[key]
            self.vals[index] = val
        else:
            self.dict[key] = len(self.keys)
            self.keys.append(key)
            self.vals.append(val)

    def __contains__(self, key: K) -> bool:
        return key in self.dict

    def __len__(self) -> int:
        return len(self.keys)

    def random_key(self) -> K:
        return self.keys[random.randrange(len(self.keys))]

下面是一个字典类的Python代码，它可以在O(1)时间内返回随机键。(为了可读性，我在代码中包含了myypy类型):

from typing import TypeVar, Generic, Dict, List
import random

K = TypeVar('K')
V = TypeVar('V')
class IndexableDict(Generic[K, V]):
    def __init__(self) -> None:
        self.keys: List[K] = []
        self.vals: List[V] = []
        self.dict: Dict[K, int] = {}

    def __getitem__(self, key: K) -> V:
        return self.vals[self.dict[key]]

    def __setitem__(self, key: K, val: V) -> None:
        if key in self.dict:
            index = self.dict[key]
            self.vals[index] = val
        else:
            self.dict[key] = len(self.keys)
            self.keys.append(key)
            self.vals.append(val)

    def __contains__(self, key: K) -> bool:
        return key in self.dict

    def __len__(self) -> int:
        return len(self.keys)

    def random_key(self) -> K:
        return self.keys[random.randrange(len(self.keys))]

因为这是家庭作业:

签出random.sample()，它将从列表中选择并返回一个随机元素。可以使用dict.keys()获得字典键列表，使用dict.values()获得字典值列表。

>>> import random
>>> d = dict(Venezuela = 1, Spain = 2, USA = 3, Italy = 4)
>>> random.choice(d.keys())
'Venezuela'
>>> random.choice(d.keys())
'USA'

通过随机调用。选择字典的键(国家)。

b = { 'video':0, 'music':23,"picture":12 } 
random.choice(tuple(b.items())) ('music', 23) 
random.choice(tuple(b.items())) ('music', 23) 
random.choice(tuple(b.items())) ('picture', 12) 
random.choice(tuple(b.items())) ('video', 0) 

试试这个(使用随机。物品选择)

import random

a={ "str" : "sda" , "number" : 123, 55 : "num"}
random.choice(list(a.items()))
#  ('str', 'sda')
random.choice(list(a.items()))[1] # getting a value
#  'num'