在一行程序中限制字典的大小

from collections import OrderedDict

# 创建一个有序字典，并设置最大长度为5
my_dict = OrderedDict(maxlen=5)

# 向字典中添加元素
my_dict['a'] = 1
my_dict['b'] = 2
my_dict['c'] = 3
my_dict['d'] = 4
my_dict['e'] = 5

# 打印字典内容
print(my_dict)  # 输出：OrderedDict([('a', 1), ('b', 2), ('c', 3), ('d', 4), ('e', 5)])

# 再次向字典中添加元素，超过最大长度时会自动删除最早添加的元素
my_dict['f'] = 6

# 打印字典内容
print(my_dict)  # 输出：OrderedDict([('b', 2), ('c', 3), ('d', 4), ('e', 5), ('f', 6)])