递归和列表理解？

Question

is "lst[1:-1]" any different from "lst[1:]"? in this situation:

def is_pal(string):
    if len(string) < 2:
        return True
    elif string[0] != string[-1]:
        return False
    else:
        return is_pal(string[1:-1]) 

The code is Checking whether string is palindrome.

Answer 1

-1 is exclusive, meaning [1:-1] will return the whole string except for the first (0) and the last characters.

BTW you can just reverse the text and check it that way:

def is_pal(string):
    return string[::-1] == string

Answer 2

consider a string,

s = "abcdef"

s[1:] = "bcdef"

s[1:-1] = "bcde"

To check whether the given string is palindrome or not, just compare the given string s with string s[::-1] .