Decorators and buffer flushing

[castironpi at gmail.com]

On Feb 28, 11:49 am, "Ethan Metsger" <emets... at obj-sys.com> wrote:
> Hi, all.
>
> I apologize for what is perhaps a newb question.  I'm in the process of  
> transitioning our testing framework from Perl to Python.  While that alone  
> probably sets off some red flags, I'm afraid it's what I'm stuck with.
>
> I'm modeling a test with five operations:  build, execute, validate,  
> publish, and clean.  The main loop might look something like this:
>
>     with Test(...) as t:
>        t.build()
>        t.execute()
>        t.validate()
>        t.publish()
>
> At each run, I want to output a '.' to denote completion of that test  
> step.  I've been able to do this, sort of, using the following decorator  
> (edited for brevity):
>
>     def report(f):
>
>        def new(self):
>           stat = f(self);
>
>           if stat is True:
>              sys.stdout.write ('.')
>
>           else:
>              ...
>
>           sys.stdout.flush()
>
>        return new
>
> (Each one of the test functions returns True or False depending on its  
> completion status.)
>
> The problem is that rather than outputting a period after each step is  
> completed, it outputs all four of them at once.  Instead of seeing  
> progress as it happens, I get it when it's finished, even though I'm  
> flushing the output buffer.
>
> Any thoughts?
>
> Best,
>
> Ethan (emets... at obj-sys.com)http://uppertank.net/ethanm/

Can you reproduce the bug on the console?  Or, try starting with a new
line in the output.  Or, try a input().