1. 声明
fruit = {}
2. 添加
# 声明字典对象
fruit = {}
# 添加键值对
fruit["apple"] = 8
fruit["orange"] = 6
fruit["banana"] = 3
可以在声明时添加：
fruit = {
"apple":8,
"orange":6,
"banana":3
}
3. 操作
- 获取
print(fruit)
# 获取apple键对应的值
print(fruit["apple"])
--------
{'apple': 8, 'orange': 6, 'banana': 3}
8
- 遍历所有的key
for key in fruit:
print(key)
-------
apple
orange
banana
4. 案例：统计列表中水果出现的次数
fruit = ["apple","tomato","orange","grape","apple","orange","apple","tomato"]
fruit_dict = {}
# 遍历fruit列表
for item in fruit:
# 判断fruit_dict字典中是否存在item键，存在则值加1，否则设置值为1
if item in fruit_dict:
fruit_dict[item] += 1
else:
fruit_dict[item] = 1
print(fruit_dict)
---------------
{'apple': 3, 'tomato': 2, 'orange': 2, 'grape': 1}
