2.序列的常用操作 - 切片
注意:此操作不会影响序列本身,而是会得到一个新的序列
my_list = [1,2,3,4,5]
new_list = my_list[1:4] # 下标索引从1开始到4结束,不包含4,步长1
print(new_list) # 结果 [2,3,4]
my_tuple = (1,2,3,4,5)
new_tuple = my_tuple[:] # 从头开始,到最后结束,步长1
print(new_tuple) # 结果(5,4,3,2,1)
my_list= [1,2,3,4,5]
new_list = my_list[::2] # 从头开始,到最后结束,步长2
print(new_list) # 结果 [1,3,5]
my_str = '12345'
new_str = my_str[:4:2] # 从头开始,到下标索引4结束,步长2
print(new_str) # 结果 [1,3]
my_str = '12345'
new_str = my_str[::-1] # 从头(最后)开始,到尾结束,步长-1(倒叙)
print(new_str) # 结果 '54321'
my_list = [1,2,3,4,5]
new_list = my_list[3:1:-1] # 从下标索引3开始,到下标1(不含)结束,步长-1(倒叙)
print(new_list) # 结果:[4,3]
my_tuple = (1,2,3,4,5)
new_tuple = my_tuple[:1:-2] # 从头(最后)开始,到下标(不含)结束,步长-2(倒叙)
print(new_tuple) # 结果:(5,3)
my_str = '万过薪月,员序程马黑来,nohtyP学'
new_str = my_str[5:10][::-1]
print(new_str)
new_str1 = my_str.split(",")[1].replace('来','')[::-1]
print(new_str1)
## 输出 黑马程序员