On 29 December 2010 14:40, Paul Moore <p.f.moore@gmail.com> wrote:
On 29 December 2010 13:36, Michael Foord <fuzzyman@voidspace.org.uk> wrote:
> Hello all,
>
> I often use python as a calculator or for simple operations using -c. It
> would be enormously useful if python -c "..." would output on stdout the
> result of the last evaluated expression in the same way that the interactive
> interpreter does.
>
> The following outputs nothing:
>
>     python -c "12 / 4.1"
>
> So you always have to prefix expressions with print to see the result.

I like the idea, but that's a fairly big semantic change. What about
adding an -e option that takes an expression, and prints its value? So
you'd have

   python -e "12 / 4.1"

(AFAICT, -e is unused at present).


That would be great. I did worry that changing the output would be backwards incompatible with code that shells out to Python using "-c", so a different command line option would be great. So long as it works with multiple statements (semi-colon separated) like the current "-c" behaviour.

I use this trick for finding the source code of Python modules:

$ python -c "import os;print os.__file__[:-1]"
/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/os.py

Often in the form:

$ mate `python -c "import module;print module.__file__[:-1]"`

All the best,

Michael Foord

 

Paul.
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