On 23/02/2023 09.05, Hen Hanna wrote:
> py bug.py
Traceback (most recent call last):
File "C:\Usenet\bug.py", line 5, in <module>
print( a + 12 )
TypeError: can only concatenate str (not "int") to str
Why doesn't Python (error msg) do the obvious thing and tell me
WHAT the actual (offending, arg) values are ?
In many cases, it'd help to know what string the var A had , when the
error occurred.
------------ i wouldn't have to put print(a) just
above, to see.
In some ways, providing this information seems appropriate. Curiously,
this does not even occur during an assert exception - despite the
value/relationship being the whole point of using the command!
x = 1
assert x == 2
AssertionError (and that's it)
Then again, remember that exceptions can be 'caught'. So, such data
would need to be added to the exception-instance. This could become
quite costly.
What are the appropriate tools for the job?
Don't add an extra print(), use a debugger.
Not only does this allow you to breakpoint critical points in the code,
but identifiers can be watch-ed and changes noted. The other handy
feature is being able to correct the current erroneous value of the
identifier and continue execution.
For us, memory-challenged coders, there is no need to remember to remove
the print() again, afterwards.
The TypeError indicates a problem between the programmer's ears. What
was thought to be a string or an integer was the opposite. This seems to
be playing fast-and-loose with Python's dynamic-typing. To quote: "we're
all adults here". Thus, I wouldn't recommend 're-cycling' an identifier
to represent two different (types of) data-point in the same code - but
there's nothing to stop you/anyone!
The other possibility is that it was an accident. Sounds more like
something I would do, but... In this case, the tool which is your/my
friend is typing. The IDE should catch most of the situations where an
int would be used as an str, or v-v. Remember though, Python's typing is
(a) not part of the language, and (b) probably won't help at run-time.
PS are you aware that there is a Python-Tutor list for the use of people
learning Python?
--
Regards,
=dn
--
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