[Pythonmac-SIG] \r in string causes eval to fail

[Bob Ippolito]

On Sep 10, 2004, at 2:25 PM, Kevin Altis wrote:

> I've run into a problem with eval on the Mac and I'm not sure whether 
> it is a bug or expected behavior. The problem is that if \r is used as 
> the line terminator instead of \n then it causes eval to fail. I ran 
> into this while copying and pasting some text to eval and the 
> clipboard had converted my newlines to returns. Here is an example 
> done in the shell. As you can see below, using newlines as a separator 
> is fine, but return (\r) isn't. This would probably only come up on 
> the Mac where return (CR, \r) is the default line terminator, but I 
> didn't know whether universal newlines support was supposed to deal 
> with this kind of issue.
>
> >>> s = """{'type':'Button',\r'name':'Button1',\r'position':(10, 
> 10),\r'label':'Button1',\r}"""
> >>> s2 = s.replace('\r', '\n')
> >>> eval(s2)

"Universal newlines" is only a mode for the file object (as far as I 
know anyway).  eval and compile take strings.

It would be a lot more portable to do this to normalize your input 
strings:

'\n'.join(s.splitlines())

splitlines is essentially universal newlines support at the string 
level.  It might be smart to do this internally, maybe this deserves a 
feature request or bug report?

-bob