On 12/03/13 05:57, RJ Ewing wrote:
I am trying to implement rot 13 and am having troubles. My code is as
follows:
There are better ways to do what you are doing but assuming this is a
learning exercise rather than a serious project I'll make some comments:
def rot_text(self, s):
ls = [i for i in s]
for i in ls:
You could have looped directly over s and built a new list to return.
Just a thought.
if i.isalpha():
if i.isupper():
Since the code in the upper and lower sections are nearly identical you
can avoid the repetition by assigning the test char (M or m) here and
then using a single block to do the conversion.
test = 'M'
else: # must be lower
test = 'm'
Or more concisely
test = 'M' if i.isupper() else 'm'
if i <= test:
x = ls.index(i)
ls[x] = chr(ord(i) + 13)
elif i > test:
x = ls.index(i)
ls[x] = chr(ord(i) - 13)
The elif could just as well be an else...
You never used x originally, but then here you do....
but it would have been easier to get it at the start
of the loop with:
for index, char in enumerate(ls):
And that would be more readable names too...
However, given the relatively small character set and fixed target a
simple mapping table would be easier to implement as suggested by
another poster.
Now if I enter abc, I get nop. But if I enter abcdefghijklmnop, I
get abcqrstuvwxyznop.
No idea what is going on there. But you are returning ls - the list. I
would have thought you'd want to return the string version of the list?
return ''.join(ls)
maybe?
--
Alan G
Author of the Learn to Program web site
http://www.alan-g.me.uk/
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