Nidian Job-Smith wrote:
Hi all,
I'm new to programming (thus Python), so after reading the basics, I wanted to
practise what I've learnt . I've come across a beginners exercise which is to
programme rot13.
I've written some code but it doesn't seem to work....
Here it is:
def rot13(s): char_low = () result = "" if not s.isalpha(): return char char_low = char_low.lower() if char_low <= 'm': dist = 13 else: dist = -13 char = chr(ord(char) + dist) def rot13_char(ch): return ''.join( rot13(s) for char in ch )
Any idea where i'm wrong?
Hi Nidian,
If possible, please send code as plain text emails, not so-called
"rich-text" (actually HTML), as it tends to mangle the formatting and
make it almost impossible to decipher for some people.
Also, please choose a meaningful subject line, to make it easier for
people to follow the conversation.
Some comments on your code, if I have re-created the formatting correctly.
(1) You seem to have mixed up strings and characters. You have a
function called "rot13" with an argument called "s" (for "string"), but
it is intended to operate on a single character. On the other hand, you
have a function called "rot13_char" with an argument "ch" (for
"character"), but it operates on an entire string! You should reverse them:
rot13(s) => apply rot13 to an entire string, s
rot13_char(c) => apply rot13 to a single character, c
(2) You have a lot of inconsistent variable names. For example, in your
version of "rot13_char" (which actually operates on an entire string,
not a character), you have:
def rot13_char(ch):
return ''.join( rot13(s) for char in ch )
Inside the join(), you have a loop "for char in ch" (for character in
character???) but then you refer to "s". This should be written as:
def rot13(string):
return ''.join(rot13_char(char) for char in string)
Likewise in the "rot13" function (better named rot13_char), you
inconsistently refer to variables by different names. You must be
consistent.
Does that give you enough hints to continue? If not, ask any more
questions you like!
--
Steven
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