Python字典的增删改操作

Key的判断

in 指定的key在字典中存在返回True，'张三' in scores

not in 指定的key在字典中不存在返回True，'Marry' not in scores

字典元素的删除

del scores['张三']

字典元素的新增

scores['Jack'] = 90

# key的判断
scores = {'张三':100, '李四':98, '王五':45}
print('张三' in scores)
print('张三' not in scores)

# 删除指定键值对
del scores['张三']
print(scores)

#清空字典的元素
scores.clear()
print(scores)

# 增加字典元素
scores['陈六'] = 98
print(scores)

# 修改字典元素
scores['陈六'] = 100
print(scores)