Flag control variable
gary.herron at islandtraining.com
Tue Feb 11 20:20:27 CET 2014
On 02/11/2014 11:01 AM, luke.geelen at gmail.com wrote:
> when using python script.py 2 \* 2 i get Traceback (most recent call
> last): File "math2.py", line 5, in <module> sign = int(sys.argv)
> ValueError: invalid literal for int() with base 10: '*'
Stop trying to guess what is going on. Print out sys.argv, and *see*
what values are there. Then read the error message.
You wrote your script expecting sys.argv to contain an int, but in
fact (according to the error) it contains a '*' -- which can't be
converted to an integer obviously. Your error is in running the script
incorrectly, *OR* in your understanding of how the command line
arguments get placed in sys.argv. In either case you best bet is to
examine sys.argv by printing it (or examining it within a debugger) and
*see* what values it contains. Then adjust your script (or the running
of it) accordingly.
These are very beginner level debugging suggestions. If you develop the
skill to read and understand the error messages, and the skill to print
(or otherwise examine) the values your program is dealing with, you
progress will by 100's of times faster then this slow wait for someone
to respond to on this list.
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