On Nov 6, 7:11 am, [EMAIL PROTECTED] wrote: > On Nov 6, 1:02 pm, "[EMAIL PROTECTED]" <[EMAIL PROTECTED]> > wrote: > > > On Nov 6, 4:27 pm, [EMAIL PROTECTED] wrote: > > > > Hi, > > > > I am using a small python file as an input file (defining constants, > > > parameters, input data, ...) for a python application. > > > The input file is simply read by an exec statement in a specific > > > dictionary, and then the application retrieve all the data it need > > > from the dictionary... > > > Everything is working nicely, but I'd like to have something a little > > > bit more robust regarding input file errors: now > > > any error in the python input script raise an exception and stop the > > > execution. > > > What I am trying to do is to execute it "step-by-step", so that I can > > > capture the exception if one line (or multi-line statement) fails, > > > print a warning about the failure, and continue the execution fo the > > > following lines/statements. Of course, an error on one line can > > > trigger errors in the following lines, but it does not matter in the > > > application I have in mind, the goal is to parse as much of the input > > > script as possible, warn about the errors, and check what's inside the > > > dictionary after the exec. > > > One way to do it is to read the input script line per line, and exec > > > each line in turn. However, this is not convenient as it does not > > > allow multi-line statements, or basic control flow like if - else > > > statements or loops. > > > Do you have control over the input file generation ? If the input file > > can be easily divided into self sufficient blocks of code, you could > > read each block in one at a time and do a compile() and exec(). Your > > input file need not be a full python script too, you could just have > > token delimited blocks of python code which are read in 1 block at a > > time and then exec(). > > > -srp > > > > Is there a better way for a step-by-step exec? Syntax errors in the > > > input script are not really a problem (as it is generated elsewhere, > > > it is not directly edited by users), although it would be nice to > > > catch. The biggest problem are runtime errors (attribute error, value > > > error, ...). Maybe compiling the file into a code object, and > > > executing this code object step-by-step in a way similar to debug? pdb > > > module should do something similar.... > > > > Best regards, > > > > Greg. > > Thanks for your input! > I had a similar solution in mind (with continuation comments to be > able to read multi-line statements, instead of statement delimiters, > but > I think your delimiter idea would be easier to implement). > The only problem is that files generated by current and older version > of the input generator (which do not have any kind of statement > delimiter) > will not be readable, or, if we just consider old file as one big > statement, will not offer the step-by-step execution. It would work > nice with new files, > but the best solution would be something that work also with older > auto-generated files... > > In fact, the error in the input script are mainly caused by version > mismatch, and the step-by-step approach is > mainly for improving backward compatibility. > Having better backward compatibility starting from now on would be > nice, but having backward compatibility with previous versions would > be even better ;-) > contains multi-line statements
Check out the InteractiveConsole and InteractiveInterpreter classes. Derive a subclass and override the 'push' method. It's not documented so you'll have to examine the source to find out exactly when and what to override. -- http://mail.python.org/mailman/listinfo/python-list
