目录
查找
index()
count()
len()
in 与 not in
增加
append()
extend()
insert()
删除
del
pop()
remove()
clear()
修改
修改序列列表指定位置
reverse()
sort()
copy()
while 和 for 循环 list 序列列表
while
for
查找
index()
语法： 列表序列.index(数据，开始下标，结束下标)
list = ["1","2","hello","world","weifei"]
# 结果：'hello' is not in list , 查找不到会报错！
print(list.index("hello",0,1))
# 结果：2
print(list.index("hello",2))
# 结果：2
print(list.index("hello"))默认不写开始下标与结束下标时，查找整个 list 列表。
如果查找的数据不存在则报错！
返回数据在 list 列表中的下标位置。
count()
语法：列表序列.count(数据)
list = ["1","2","hello","world","1","weifei","1"]
# 结果：3
print(list.count("1"))
# 结果：1
print(list.conut("hello"))count 方法返回数据在 list 列表中存在的总数量。
注意： 总数量跟下标不同，从1开始，并不是从0，有多少个就是多少个。
len()
语法：len(列表序列)
list = ["1","2","hello","world","1","weifei","1"]
print(len(list))# 结果：7
list1 = ["1","2","3"]
print(len(list1))# 结果：3
list2 = ["A","B","C","D"]
print(len(list2))# 结果：4len 方法访问列表长度，即列表中数据的个数。
in 与 not in
语法：
in ----- 指定数据 in 列表序列
not in ------ 指定数据 not in 列表序列
# in 例子：
list = ["1","2","hello","world","1","weifei","1"]
print("hello" in list) # 结果：True
print("wei" in list) # 结果：False
print("1" in list) # 结果：True# not in 例子:
list = ["1","2","hello","world","1","weifei","1"]
print("hello" not in list) # 结果：False
print("wei" not in list) # 结果：True
print("1" not in list) # 结果：False存在指定数据，存在指定数据时返回 True ，否则返回 False 。
not in 判断列表序列中是否不存在指定数据：不存在指定数据时返回 True ,否则返回 False 。
增加
append()
语法：列表序列.append(指定数据)
list = ["2",2,"hello"]
list.append("world")
# 结果：["2",2,"hello","world"]
print(list)
list.append("weifei")
# 结果：["2",2,"hello","world","weifei"]
print(list)
list.append(["你好","我不好，我阳了"])
# 结果：["2",2,"hello","world","weifei",["你好","我不好，我阳了"]]
print(list)append 方法向列表序列末尾添加指定数据。
列表追加数据的时候，直接在原列表里面追加了指定数据，即修改了原列表，故列表为可变数据类型。
注意：如果append()追加的数据是一个序列，则追加整个序列到列表。
extend()
语法：列表序列.extend(数据)
list = ["wei","fei"]
list.extend("CSDN")
# 结果：['wei', 'fei', 'C', 'S', 'D', 'N']
print(list)list = ["wei","fei"]
list.extend(["CSDN","666"])
# 结果：["wei","fei","CSDN","666"]
print(list)extend 方法在列表末尾添加数据，如果该数据是一个序列，则将这个序列的数据进行逐一添加到列表。
insert()
语法：列表序列.insert(位置下标，数据)
list = ["1","2","CSDN"]
list.insert(0,"weifei")
# 结果：["weifei","1","2","CSDN"]
print(list)
list.insert(2,"666")
# 结果：["weifei","1","666","2","CSDN"]
print(list)insert 方法向列表序列指定下标位置添加数据。
删除
del
语法 ： del 目标
list = ["weifei","CSDN","66666"]
# 结果：["weifei","CSDN","66666"]
print(list)
del list[2]
# 结果：["weifei","CSDN"]
print(list)
del list
# 结果：'list' is not defined
print(list)del 可以删除整个数据也可以删除指定数据。
删除指定数据时需要在列表序列后面添加需要删除的下标位置。
pop()
语法：列表序列.pop(下标)
list = ["weifei","CSDN","66666","233"]
list.pop()
# 结果：["weifei","CSDN","66666"]
print(list)
list.pop(0)
# 结果：["CSDN","66666"]
print(list)pop 方法删除指定下标数据，默认为删除最后一个。
remove()
语法： 列表序列.remove(数据)
list = ["666","weifei","CSDN","666","233","666"]
list.remove("666")
# 结果：["weifei","CSDN","666","233","666"]
print(list)remove 方法移除列表序列中匹配到的第一个数据项。
clear()
语法：列表序列.clear()
list = ["666","weifei","CSDN","666","233","666"]
list.clear()
# 结果：[]
print(list)clear 方法，清空列表序列中的所有数据，即清空列表。
修改
修改序列列表指定位置
语法：序列列表[下标] = 数据
list = ["666","weifei","CSDN","666","233","666"]
list[0] = "你好"
# 结果：["你好","weifei","CSDN","666","233","666"]
print(list)该方法通过下标来获取到当前数据，并通过 = 重新赋值的方法来达到修改列表指定位置的效果。
reverse()
语法：序列列表.reverse()
list = ["1","2","3","4","5","6"]
list.reverse()
#结果： ["6","5","4","3","2","1"]
print(list)reverse 方法会将列表数据进行逆置，即反转数据。
sort()
语法：列表序列.sort(key=None,reverse=False)
list = ["1","8","3","2","6"]
list.sort()
# 结果：["1","2","3","6","8"]
print(list)
list.sort(reverse=True)
# 结果：['8', '6', '3', '2', '1']
print(list)sort 方法会将列表进行排序。
reverse表示排序规则，reverse=True降序，reverse=Flase升序（默认）
copy()
语法：序列列表.copy()
list1 = ["weifei","CSDN","666","233"]
list2 = list1.copy()
# 结果： ["weifei","CSDN","666","233"]
print(list2)copy 方法会将列表进行复制并返回一个一模一样的列表。
while 和 for 循环 list 序列列表
while
list = ["CSDN","weifei","hello","world"]
i = 0
while i < len(list):
"""
打印结果：
CSND
weifei
hello
world
"""
print(i)
i += 1for
list = ["CSDN","weifei","hello","world"]
for i in list:
"""
打印结果：
CSND
weifei
hello
world
"""
print(i)
