訪問元組
通過·索引取數(shù)據(jù)：
aTuple=(23,35,56,34,11,21)
print(aTuple[2])
索引值存在：#56
索引值不存在：報(bào)錯(cuò)
查詢個(gè)數(shù)
count查詢出現(xiàn)個(gè)數(shù)
aTuple=('b','c','d','e','f','g')
print(aTuple.count('d'))
#1
查詢索引
aTuple=('b','c','d','e','f','g')
print(aTuple.index('d',0,4))
有對(duì)應(yīng)元素：#2
無對(duì)應(yīng)元素：報(bào)錯(cuò)
列表轉(zhuǎn)元組
aa=[23,34,45,56,67]
cc=tuple(aa)
print(cc)
#（23, 34, 45, 56, 67）
元組轉(zhuǎn)列表
bb=("b","c","d","f","g")
a=list(bb)
print(a)
#['b', 'c', 'd', 'e', 'f', 'g']
元組循環(huán)取值
aa=[22,45,58,90]
for i in aa:
print(i)
#[22,45,58,90]
while循環(huán)：
aa=[22,45,58,90]
i=0
while i<len(aa):
print(aa[i])
i+=1
字典
根據(jù)鍵訪問值
info = {"name":"111","age":18,"sex":"男"}
有對(duì)應(yīng)的key
print(info["name"])
#111
無對(duì)應(yīng)的key：報(bào)錯(cuò)
不確定字典中是否存在某個(gè)鍵而又想獲取其值時(shí),如何操作？
有對(duì)應(yīng)key的
info = {"name":"111","age":12,"sex":"男"}
print(info.get("name"))
#111
無對(duì)應(yīng)key的
info = {"name":"anfly","age":12,"sex":"男"}
print(info.get("name"))
#None
無對(duì)應(yīng)key的,默認(rèn)返回?cái)?shù)據(jù)
info = {"name":"anfly","age":12,"sex":"男"}
print(info.get("name12","無數(shù)據(jù)"))
#無數(shù)據(jù)
修改元素：
字典的每個(gè)元素中的數(shù)據(jù)是可以修改的，只要通過key找到，即可修改,否則是新增
對(duì)應(yīng)的key
info = {"name":"anfly","age":12,"sex":"男"}
info["age"] =14
print(info)
#{'name': 'anfly', 'age': 14, 'sex': '男'}
無對(duì)應(yīng)的key
info = {"name":"anfly","age":12,"sex":"男"}
info["gender"] ="屬雞"
print(info)
#{'name': 'anfly', 'age': 12, 'sex': '男', 'gender': '屬雞'}
添加元素：
info = {"name":"anfly","age":12,"sex":"男"}
info["gender"] ="屬雞"
print(info)
#{'name': 'anfly', 'age': 12, 'sex': '男', 'gender': '屬雞'}
刪除元素：
刪除整個(gè)字典
info = {"name":"anfly","age":12,"sex":"男"}
del info
print(info)
#NameError: name 'info' is not defined
刪除某個(gè)元素
info = {"name":"anfly","age":12,"sex":"男"}
del info["name"]
print(info)
#{'age': 12, 'sex': '男'}
清空：
info = {"name":"anfly","age":12,"sex":"男"}
info.clear()
print(info)
#{}
查詢長(zhǎng)度：
info = {"name":"anfly","age":12,"sex":"男"}
print(len(info))
#3
字典中的循環(huán)：
取出字典中的key
info = {"name":"anfly","age":12,"sex":"男"}
for i in info.keys():
? print(i)
取出·字典中的value
info = {"name":"anfly","age":12,"sex":"男"}
for i in info.values():
? ? rint(i)
取出字典中的key和value
方法一：
info = {"name":"anfly","age":12,"sex":"男"}
for i in info.keys():
? ? print(i,info[i])
方法二：
info = {"name":"anfly","age":12,"sex":"男"}
for k,v in info.items():
? ? print(k,v)
enumerate()實(shí)現(xiàn)索引的遍歷：
names=["anfly","tom","Meachal"]
for i,chr in enumerate(names):
? print(i,chr)
