Python基本数据结构之字典类型dict用法分析

a = dict(one=1, two=2, three=3)
b = {'one': 1, 'two': 2, 'three': 3}
c = dict(zip(['one', 'two', 'three'], [1, 2, 3]))
d = dict([('two', 2), ('one', 1), ('three', 3)])
e = dict({'three': 3, 'one': 1, 'two': 2})
print(a == b == c == d == e)

d = {'Name': 'Zara', 'Age': 7, 'Class': 'First'};
print(d['Name'],d['Age'],d['Class'])      # 访问键值访问 dict_name['key_name']
print("%s's age is %d, class is: %s." %(d['Name'], d['Age'],d['Class']))  # 字符串输出
# print(d['name'])         # 无该键值，会报错，注意大小写
d['Age'] = 8
print(d['Age'])          # 可直接修改键的数值，数值类型不限

d = {'Name': 'Zara', 'Age': 7, 'Class': 'First'};
print(d['Name'],d['Age'],d['Class'])      # 访问键值访问 dict['key_name']
print("%s's age is %d, class is: %s." %(d['Name'], d['Age'],d['Class']))  # 字符串输出
# print(d['name'])        # 无该键值，会报错，注意大小写
d['Age'] = 8
print(d['Age'])          # 可直接修改键的数值，数值类型不限
print('Name' in d)        # 判断键是否存在
print('xxx' not in d)       # 判断键是否不存在
d['Sex'] = "Female"        # 增加键值直接赋值即可
print(d)
del d['Class']          # 删除键值
print(d)
# del d['Class']         # 若无键值，会报错
d.clear()             # 清空dict
print(d)

d = {'Name': 'Zara', 'Age': 7, 'Class': 'First'};
print(len(d))          # 键值的组合数量
print(d.keys(),type(d.keys()))  # 为dict_keys 类型，可list()转换为list 或 set()转换为set
print(d.values())        # 为dict_values 类型
print(d.items())         # 为dict_items 类型