for 循环

1、for 循环—for 便利：列表、字典、元祖、字符串/

2、break :退出循环

3、continue :跳过本轮循环，不执行continue之后的代码。直接进入下一轮循环

 

new_list = ["玖yue", "柠檬", "人生", "leisen", "Bodhi", "饭团"]

 

# 1、遍历列表的值(成员)
for item in new_list:
    print(f"哈罗，{item}")
    if item == "人生":
        continue

# 2、遍历列表的下标，通过下标去取值 [0,1,2,3...]
for index in range(len(new_list)):
    # print(index) # 索引
    # print(new_list[index]) # 索引对应的值
    print("索引为 {} 的值是: {}".format(index,new_list[index]))

 

 

 

4、有一个生成整数列表的方法：range

range([起始整数],结束整数,[步长])   起始整数默认为0，步长默认为1  左闭右开(取头不取尾)
range(5) => [0,1,2,3,4]
range(1,5) => [1,2,3,4]
range(1,10,2)  => [1,3,5,7,9]

5、字典的遍历：key --value
(1)遍历  key

for key in dict.keys()

(2)遍历 key --value

for item in person_info.items():
    print(item)

for key,value in person_info.items():
    print(key,value)

person_info = {"name": "xj", "age":18, "city": "长沙", "girl": ""}
for key in person_info.keys():
    print(key)

 

 

print(person_info.items())  #dict_items([('name', 'xj'), ('age', 18), ('city', '长沙'), ('girl', '')])

 

 

for item in person_info.items():
    print(item)

 

 

for key,value in person_info.items():
    print(f"{key}: {value}")