【Python】回文palindrome——利用字符串反转

回文

palindrome

Python

字符串反转string[::-1]

Slice notation "[a : b : c]" means "count in increments of c starting at a inclusive, up to b exclusive".

If c is negative you count backwards, if omitted it is 1.

If a is omitted then you start as far as possible in the direction you're counting from (so that's the start if c is positive and the end if negative).

If b is omitted then you end as far as possible in the direction you're counting to (so that's the end if c is positive and the start if negative).

If a or b is negative it's an offset from the end (-1 being the last character) instead of the start.

回文

###############################################
#       Exercise by Websten from forums       #
###############################################
# A palindrome is a word or a phrase that reads
# the same backwards as forwards. Make a program
# that checks if a word is a palindrome.
# If the word is a palindrome, print 0 to the terminal,
# -1 otherwise.
# The word contains lowercase letters a-z and
# will be at least one character long.
#
### HINT! ###
# You can read a string backwards with the following syntax:
# string[::-1] - where the "-1" means one step back.
# This exercise can be solved with only unit 1 knowledge
# (no loops or conditions)

word = "madman"
# test case 2
# word = "madman" # uncomment this to test

###
# YOUR CODE HERE. DO NOT DELETE THIS LINE OR ADD A word DEFINITION BELOW IT.
###
#自己的代码
is_palindrome = word.find(word[::-1])

# TESTING
print is_palindrome
# >>> 0  # outcome if word == "madam",a palindrome
# >>> -1 # outcome if word == "madman",not a palindrome