列表和元组的一些笔记

Posted 2020-10-30 chency2018

#列表
# 1. 列表格式
# 2. 列表中可以嵌套任何类型
li = [1,2,3,["分割线",23,45],"sljfg",True,(23,),{"jiwei":23},] #列表中的元素可以是 数字，字符串,列表，布尔值,元组，字典
print(li)
# 3索引,索引从0开始计数，
print(li[0])#li[0]对应li中的第一个元素1
#4 切片，输出后还是列表
print(li[1:-1])#其中-1是右边第一个元素，[1:-1]是切片从左边第二个元素到右边第一个元素之间元素
#5for循环
li = [1,2,3,["分割线",23,45],"sljfg",True,(23,),{"jiwei":23},]
for item in li:
    print(item)

#6 索引
li = [1,2,3,["分割线",23,45],"sljfg",True,(23,),{"jiwei":23},]
li[0] = 10 #可以数字和改成其他类型
print(li)
li[1] = [2,3,456]

# 删除
del li[1]
print(li)

#7 切片
li = [1,2,3,["分割线",23,45],"sljfg",True,(23,),{"jiwei":23},]
li[2:4] = [234,3455]
print(li)
# 删除某段切片
del li[1:3]
print(li)

# 8in 的操作
li = [1,2,3,["分割线",23,45],"sljfg",True,(23,),{"jiwei":23},]
w ="sljfg" in li
print(w)

# 9字符串可以直接转换成列表
b = "suogiwoehgoiahgiai"
new_list = list(b)
print(new_list)
# 列表转换成字符串
li = [11,22,33,"123","alex"]
r = str(li) # 将列表改变成字符串‘[11,22,33,"123","alex"]‘
print(r)
# 将字符串拼接打印
s = ""
for i in li:
    s = s + str(i)
print(s)