# -- coding: utf-8 --
# @time : 2022/7/19 21:51
# @file : 10pytest基本数据类型-dic.py
# @software: pycharm

D = {"a": "123",
     "b": "456",
     "c": 888}
D.copy()
print(id(D))
print(id(D.copy()))
print(D.copy())  # D的浅拷贝

print(D.get("a"))  # 获取key为"a"的值 D["a"] if a in D, else d.  d defaults to None.
print(D.items())  # dict_items([('a', '123'), ('b', '456'), ('c', 888)])
print(D.keys())  # 返回字典中所有的key dict_keys(['a', 'b', 'c'])
print(D.values())  # 返回字典中所有的值 dict_values(['123', '456', 888])
# print(D.pop("1"))  #KeyError: '1'
print(D.pop("a"))  # 移除key为"a"并输出key对应的值 123
print(D.popitem())  # 返回并删除字典中的最后一对键和值。('c', 888)
print(D.items())

print(D.setdefault("b"))  # 如果key-b在D里边存在，则返回D.get(b),和get类似
print(D.setdefault("c", "999"))  # also set D[c]=999 if c not in D
print(D.setdefault("d", "777"))  # also set D[d]=777 if d not in D

print(D.items())
print(D.clear())  # 清空字典  返回None.  Remove all items from D.

print("============以上方法为python-字典的内置方法==================")



# 除了以上方法外，还有以下常用的方法
D["e"] = 000
D["f"] = "你好呀"
print(D)
print(D["f"])  # 访问字典里边的值
D["f"] = "我不好"  # 修改字典
print(D)
del D["f"]  # 删除字典元素
print(D)
print(len(D))  # 计算字典的键的总数。
print(type(D))  # 返回输入的变量类型
print(str(D))  # 输出字典可打印的字符串表示。