[Python-Dev] String concatenation

[Isaac Morland]

On Sat, 23 Aug 2008, Fredrik Lundh wrote:

> removing it is a bad idea for the reasons already given, but requiring 
> parentheses could help.
>
> that is, the following would result in a warning or an error:
>
>    L = ["first", "second" "third"]
>
> but the following wouldn't:
>
>    L = ["first", ("second" "third")]
>
>    T = ("This is a line of text.\n"
>         "This is another line of text.\n")

This would avoid accidentally leaving out commas in list construction, but 
tuple construction would still have the same problem.  And it's still a 
change in the language which would probably affect lots of existing code. 
I doubt if there is any problem-free way of trying to address this issue 
by changing the language.

One suggestion to help minimize problems when writing code would be always 
to put the optional trailing comma:

[
 	'a',
 	'b',
 	'c',
]

which is also a revision-control-friendly practice, and in the tuple 
constuction context avoids the possibility of removing an item from a 
two-tuple and ending up with not a one-tuple but instead just the item 
itself.

Isaac Morland			CSCF Web Guru
DC 2554C, x36650		WWW Software Specialist