如果可能有重复键,如何添加到字典？

my_dict = {}

key = "key1"
value1 = "value1"
value2 = "value2"

if key in my_dict:
    my_dict[key].append(value1)
else:
    my_dict[key] = [value1]

if key in my_dict:
    my_dict[key].append(value2)
else:
    my_dict[key] = [value2]

my_dict = {}

key = "key1"
value1 = "value1"
value2 = "value2"

if key in my_dict:
    my_dict[key] += (value1,)
else:
    my_dict[key] = (value1,)

if key in my_dict:
    my_dict[key] += (value2,)
else:
    my_dict[key] = (value2,)

from collections import defaultdict

my_dict = defaultdict(list)

key = "key1"
value1 = "value1"
value2 = "value2"

my_dict[key].append(value1)
my_dict[key].append(value2)

from collections import Counter

my_dict = {}

key = "key1"
value1 = "value1"
value2 = "value2"

if key in my_dict:
    my_dict[key] = Counter(my_dict[key])
    my_dict[key][value1] += 1
else:
    my_dict[key] = Counter({value1: 1})

if key in my_dict:
    my_dict[key][value2] += 1
else:
    my_dict[key] = Counter({value2: 1})