python dict

# 字典是一种无序的集合,通常用于描述某个对象的信息
user = {
        "name": "wyc",
        "age": 22,
        "gender": "male"
       }

# 取值
print(user["name"])

# 根据key来取值,不存在则返回设置的值
print(user.get("name", 0))

# saveorupdate
user["name"] = "yeye"
user["xx"] = "xx"


# 删除
user.pop("name")

# 合并字典,相同的key-value会被覆盖
user.update({"name": "xxx"})


# 清除
# user.clear()

print(user)

# 统计长度
print(len(user))


# 遍历
for key in user:
    print("%s -- %s" % (key, user[key]))


for tuples in user.items():
    print("%s ---- %s" % (tuples[0], tuples[1]))

# dict推导式
# v,k互换
my_dict = {v: k for k, v in user.items()}
print(my_dict)