#从索引start到索引stop-1进行切片
arr[start:stop]

#从索引start到结尾进行切片
arr[start:]

#从开头到索引stop-1进行切片
arr[:stop]

#从索引start到索引stop进行切片，步长为step
arr[start:stop:step]

#创建一个字符串
myStr = 'Thisisit!'

#显示字符串
print("字符串 = ", myStr)

#切片字符串
#负索引
print("切片后的字符串（使用负索引）= ", myStr[-4:-1])

字符串 = Thisisit！
切片后的字符串（使用负索引）= sit

#创建一个字符串
myStr = 'Thisisit. We did it!'

#显示字符串
print("字符串 = ", myStr)

#切片字符串
#负索引带步长
print("切片后的字符串（使用负索引）= ", myStr[-9:-3:2])

字符串 = Thisisit. We did it!
切片后的字符串（使用负索引）= edd

myStr = 'Hello! How are you?'
print("字符串 = ", myStr)

#切片
print("反向字符串 = ", myStr[::-1])

字符串 = Hello! How are you?
反向字符串 = ?uoy era woH !olleH