python列表的简单应用

li = 'asdasd'
new_li = list(li)
print(li)

for iterable in new_li:
    print(iterable)
a = ' '.join(new_li)
tu = (1,2,3,"sdsad",[2,3,5],)
print(tu[2])

for i in tu:
    print(i)
li = [13,3,2,34,"asdasd"]
li.extend(tu)#添加
li.insert(1,"rg")
li.append('ooo')
print(li)

tu[4][0] = 66#嵌套其他的列表可以改变
print(li)

print(tu.count(2))#获取制定元素出现的次数
print(tu.index(2))#返回索引

info = {'k':2,'w':3}
print(info['k'])

for k,in info.keys(): #键
     print(k)
for v in info.values(): #值
     print(v)
for k1,v1 in info.items(): #键值对
     print(k1,v1)

布尔值（True 1，False 0）
v = dict.fromkeys(['k',123,'i'],123)#根据序列创建序列，并之指定统一值
print(v)

v = {'k1':1,'k2':2}
a = v.get('k',-1)#获取值
print(a)

c = v.pop('k2')#得到删除值
print(v,c)

k1,v1 = v.popitem()
print(k1,v1)

e = v.setdefault('k3',111)#若存在获取当前值，若不存在则设置
print(e)

v.update(k1 = 123,k2 = 456,k = "asdf")#更新字典
 print(v)

keys() values() items() get updata

None [] {} 0——>False