python 3 字典的基本操作

dic = {'name': 'a', 'age': 21, 'gender': 'middle'}

# 添加
dic['habbit'] = 'a_lot'
print(dic)
{'name': 'a', 'gender': 'middle', 'habbit': 'a_lot', 'age': 21}

# 修改
dic['habbit'] = 'none'
print(dic)
{'name': 'a', 'gender': 'middle', 'habbit': 'none', 'age': 21}

# 删除
dic.pop('habbit') # or use (del dic['habbit'])
print(dic)
{'name': 'a', 'gender': 'middle', 'age': 21}

pop返回删除的值，del直接删除，不反回

# 查找
print('age' in dic)
True
print(dic.get('age')) # or use (dic['age'])
21

# others
print(dic.values())
print(dic.keys())
dict_values(['a', 'middle', 21])
dict_keys(['name', 'gender', 'age'])

# 遍历
# 方法1
for key in dic:
print(key, dic[key])

# 方法2
for k, v in dic.items(): # 会先把dict转成list,数据里大时莫用
print(k, v)