Pychecker

[Anthony Greene]

Howdy, I had the impression that pychecker caught and reported such
dynamic syntactical errors.

#!/usr/bin/env python


def add(i):
i += 10

status = 3

if 1 == 1:
statuss = 15

add(status)

=============== ========

exalted sysfault$ pychecker foo.py
Processing foo...

Warnings...

None

=============== ========

Hence the mispelling of status (statuss), which was done purposely to test
if pychecker will acknowledge and report the error. Do i need to enable
some type of pychecker option in order for it to pick up the error? I know
that it is syntactically correct in python, however it's likely that
'status' is meant. Am i wishing that pychecker will replace a statically
typed language mechanism?

--
A wise man knows he knows nothing.

[Rick Zantow]

Re: Pychecker

Anthony Greene <sysfault@zetaf unc.net> wrote in
news:pan.2006.0 6.09.18.10.58.7 46134@zetafunc. net:
[color=blue]
> Howdy, I had the impression that pychecker caught and reported such
> dynamic syntactical errors.
>
> #!/usr/bin/env python
>
>
> def add(i):
> i += 10
>
> status = 3
>
> if 1 == 1:
> statuss = 15
>
> add(status)
>
> =============== ========
>
> exalted sysfault$ pychecker foo.py
> Processing foo...
>
> Warnings...
>
> None
>
> =============== ========
>
> Hence the mispelling of status (statuss), which was done purposely to
> test if pychecker will acknowledge and report the error. Do i need to
> enable some type of pychecker option in order for it to pick up the
> error? I know that it is syntactically correct in python, however it's
> likely that 'status' is meant. Am i wishing that pychecker will
> replace a statically typed language mechanism?
>[/color]

I think you're asking a lot from pychecker.

kop = 1
koi = 2

if True:
koo = 3

What would you like pychecker to report?


--
rzed

[Matt Good]

Re: Pychecker

Anthony Greene wrote:[color=blue]
> Howdy, I had the impression that pychecker caught and reported such
> dynamic syntactical errors.
>
> #!/usr/bin/env python
>
>
> def add(i):
> i += 10
>
> status = 3
>
> if 1 == 1:
> statuss = 15
>
> add(status)
>
> =============== ========
>
> exalted sysfault$ pychecker foo.py
> Processing foo...
>
> Warnings...
>
> None
>
> =============== ========
>
> Hence the mispelling of status (statuss), which was done purposely to test
> if pychecker will acknowledge and report the error. Do i need to enable
> some type of pychecker option in order for it to pick up the error? I know
> that it is syntactically correct in python, however it's likely that
> 'status' is meant. Am i wishing that pychecker will replace a statically
> typed language mechanism?[/color]

That's a functional error, not a syntactical one. Analyzing the
spelling of variables for similarity would lead to a lot of incorrect
warnings since pychecker has no way to tell this apart from intentional
similar spellings such as:

values = [1, 2, 3]
value = values[0]

However, when the misspelling is made inside a local scope, rather than
at the module level a warning is reported "test.py:8: Local variable
(statuss) not used":

def add(i):
i += 10

def test():
status = 3
if 1 == 1:
statuss = 15
add(status)


This is why tools like pychecker (or pyflakes, pylint, or even a static
code compiler) aren't a substitute for unit tests. They can definitely
help catch common mistakes, but they can't ensure your code does what
you intended.

--
Matt Good

[skip@pobox.com]

Re: Pychecker


Rick> I think you're asking a lot from pychecker.

Rick> kop = 1
Rick> koi = 2

Rick> if True:
Rick> koo = 3

Rick> What would you like pychecker to report?

I thing the OP was hoping for a "not used" error, but it can only reasonably
do that within a function, which it does do:

pyc.py:2: Local variable (kop) not used
pyc.py:3: Local variable (koi) not used
pyc.py:6: Local variable (koo) not used

At the module level it doesn't know that the suspect object isn't accessed
from another module.

Skip

[Anthony Greene]

Re: Pychecker

On Fri, 09 Jun 2006 11:46:59 -0700, Matt Good wrote:
[color=blue]
> Anthony Greene wrote:[color=green]
>> Howdy, I had the impression that pychecker caught and reported such
>> dynamic syntactical errors.
>>
>> #!/usr/bin/env python
>>
>>
>> def add(i):
>> i += 10
>>
>> status = 3
>>
>> if 1 == 1:
>> statuss = 15
>>
>> add(status)
>>
>> =============== ========
>>
>> exalted sysfault$ pychecker foo.py
>> Processing foo...
>>
>> Warnings...
>>
>> None
>>
>> =============== ========
>>
>> Hence the mispelling of status (statuss), which was done purposely to test
>> if pychecker will acknowledge and report the error. Do i need to enable
>> some type of pychecker option in order for it to pick up the error? I know
>> that it is syntactically correct in python, however it's likely that
>> 'status' is meant. Am i wishing that pychecker will replace a statically
>> typed language mechanism?[/color]
>
> That's a functional error, not a syntactical one. Analyzing the
> spelling of variables for similarity would lead to a lot of incorrect
> warnings since pychecker has no way to tell this apart from intentional
> similar spellings such as:
>
> values = [1, 2, 3]
> value = values[0]
>
> However, when the misspelling is made inside a local scope, rather than
> at the module level a warning is reported "test.py:8: Local variable
> (statuss) not used":
>
> def add(i):
> i += 10
>
> def test():
> status = 3
> if 1 == 1:
> statuss = 15
> add(status)
>
>
> This is why tools like pychecker (or pyflakes, pylint, or even a static
> code compiler) aren't a substitute for unit tests. They can definitely
> help catch common mistakes, but they can't ensure your code does what
> you intended.[/color]

Thanks guys, exactly what was needed.
--
A wise man knows he knows nothing.