[Python-ideas] Reporting unmatched parentheses in SyntaxError messages?

Ron Adam ron3200 at gmail.com
Wed Jul 8 17:25:36 CEST 2015

On 07/08/2015 01:53 AM, Nick Coghlan wrote:
> Or, similarly,
>      SyntaxError: invalid syntax (Unmatched '[' on line 10)
>      SyntaxError: invalid syntax (Unmatched '{' on line 10)

I don't think "invalid syntax" is needed here.  SyntaxError is enough.

> I'm not sure it would be feasible though - we generate syntax errors
> from a range of locations where we don't have access to the original
> token data any more :(

Possibly another way to do this is to create a "SyntaxError token" in the 
parser with the needed information, then raise it if it's found in a later 

These aren't always found at the end of the file, they can come up when a 
brace or parentheses is mismatched.  Currently those generate the syntax 
error at the end location, but they could say why and where the other brace 
is at.

     SyntaxError: found ] , instead of )

I think it would be better if the message's did not contain the location, 
and that part was moved to the traceback instead.

Have a more general non location dependent error message is helpful for 
comparing similar Exceptions without having to filter out the numbers which 
can change between edits.

     File "/home/me/myfile.py", line 10 to 11   <----- # here
         data = func()
     SyntaxError: unmatched '('         <---- not here


More information about the Python-ideas mailing list