继续整理前段零零碎碎的python资料

一、字典补充

# 补充dict字典方法

dic={1:"china",2:"english",3:"american"}

# 取字典key，可以fon in遍历

k=dic.keys()

print(k) # dict_keys([1,2,3])

for i in k:

    print(i)

# 取字典values

v=dic.values()

print(v)  # dict_values(["china","english","american"])

# 将字典项取出（元组列表）,方便for in以拆包方式遍历

kv=dic.items()

print(kv)  # dict_items[(1,"china"),(2,"english"),(3,"american")]

for item in dic.items():

    k,v=item

    print(k,v)

解包：

a,b=(1,2)

a,b=[1,2]