Undefined variable in lambda function












3















I have the code :



from functools import reduce

public_ids = [1,2,3,4,5]
filepath = '/path/to/file/'

rdd = sc.textFile(
filepath
)

new_rdd = reduce(
lambda a, b: a.filter(
lambda x: b not in x
),
public_ids,
rdd
)


This code is suppose to filter lines in a rdd according to a list of ids. The rdd is created from files located in filepath using spark context sc's textFile method.



This code works fine, but pylint raises the error :




E: Undefined variable 'b' (undefined-variable)




I believe the way I coded it is not the proper way. How can I change it so pylint does not raise the error again ? Or is it just a structure that pylint does not recognize properly ?










share|improve this question


















  • 1





    To answer the spirit of your question, perhaps you can try actually naming your functions instead of nesting the lambdas: def func(a, b): return a.filter(lambda x: b not in x). And then call reduce(func, ...) instead. I'm guessing it had to do with scoping within anonymous functions, so naming it might help.

    – Idlehands
    Nov 14 '18 at 17:05













  • I thought that could be the issue indeed, but creating a function used only once is against my religion.

    – Steven
    Nov 14 '18 at 17:07






  • 1





    From my point of view, disposable named functions are evil! Well then you're lost! ...sorry

    – Idlehands
    Nov 14 '18 at 17:16


















3















I have the code :



from functools import reduce

public_ids = [1,2,3,4,5]
filepath = '/path/to/file/'

rdd = sc.textFile(
filepath
)

new_rdd = reduce(
lambda a, b: a.filter(
lambda x: b not in x
),
public_ids,
rdd
)


This code is suppose to filter lines in a rdd according to a list of ids. The rdd is created from files located in filepath using spark context sc's textFile method.



This code works fine, but pylint raises the error :




E: Undefined variable 'b' (undefined-variable)




I believe the way I coded it is not the proper way. How can I change it so pylint does not raise the error again ? Or is it just a structure that pylint does not recognize properly ?










share|improve this question


















  • 1





    To answer the spirit of your question, perhaps you can try actually naming your functions instead of nesting the lambdas: def func(a, b): return a.filter(lambda x: b not in x). And then call reduce(func, ...) instead. I'm guessing it had to do with scoping within anonymous functions, so naming it might help.

    – Idlehands
    Nov 14 '18 at 17:05













  • I thought that could be the issue indeed, but creating a function used only once is against my religion.

    – Steven
    Nov 14 '18 at 17:07






  • 1





    From my point of view, disposable named functions are evil! Well then you're lost! ...sorry

    – Idlehands
    Nov 14 '18 at 17:16
















3












3








3








I have the code :



from functools import reduce

public_ids = [1,2,3,4,5]
filepath = '/path/to/file/'

rdd = sc.textFile(
filepath
)

new_rdd = reduce(
lambda a, b: a.filter(
lambda x: b not in x
),
public_ids,
rdd
)


This code is suppose to filter lines in a rdd according to a list of ids. The rdd is created from files located in filepath using spark context sc's textFile method.



This code works fine, but pylint raises the error :




E: Undefined variable 'b' (undefined-variable)




I believe the way I coded it is not the proper way. How can I change it so pylint does not raise the error again ? Or is it just a structure that pylint does not recognize properly ?










share|improve this question














I have the code :



from functools import reduce

public_ids = [1,2,3,4,5]
filepath = '/path/to/file/'

rdd = sc.textFile(
filepath
)

new_rdd = reduce(
lambda a, b: a.filter(
lambda x: b not in x
),
public_ids,
rdd
)


This code is suppose to filter lines in a rdd according to a list of ids. The rdd is created from files located in filepath using spark context sc's textFile method.



This code works fine, but pylint raises the error :




E: Undefined variable 'b' (undefined-variable)




I believe the way I coded it is not the proper way. How can I change it so pylint does not raise the error again ? Or is it just a structure that pylint does not recognize properly ?







python pyspark pylint






share|improve this question













share|improve this question











share|improve this question




share|improve this question










asked Nov 14 '18 at 16:45









StevenSteven

2,67711234




2,67711234








  • 1





    To answer the spirit of your question, perhaps you can try actually naming your functions instead of nesting the lambdas: def func(a, b): return a.filter(lambda x: b not in x). And then call reduce(func, ...) instead. I'm guessing it had to do with scoping within anonymous functions, so naming it might help.

    – Idlehands
    Nov 14 '18 at 17:05













  • I thought that could be the issue indeed, but creating a function used only once is against my religion.

    – Steven
    Nov 14 '18 at 17:07






  • 1





    From my point of view, disposable named functions are evil! Well then you're lost! ...sorry

    – Idlehands
    Nov 14 '18 at 17:16
















  • 1





    To answer the spirit of your question, perhaps you can try actually naming your functions instead of nesting the lambdas: def func(a, b): return a.filter(lambda x: b not in x). And then call reduce(func, ...) instead. I'm guessing it had to do with scoping within anonymous functions, so naming it might help.

    – Idlehands
    Nov 14 '18 at 17:05













  • I thought that could be the issue indeed, but creating a function used only once is against my religion.

    – Steven
    Nov 14 '18 at 17:07






  • 1





    From my point of view, disposable named functions are evil! Well then you're lost! ...sorry

    – Idlehands
    Nov 14 '18 at 17:16










1




1





To answer the spirit of your question, perhaps you can try actually naming your functions instead of nesting the lambdas: def func(a, b): return a.filter(lambda x: b not in x). And then call reduce(func, ...) instead. I'm guessing it had to do with scoping within anonymous functions, so naming it might help.

– Idlehands
Nov 14 '18 at 17:05







To answer the spirit of your question, perhaps you can try actually naming your functions instead of nesting the lambdas: def func(a, b): return a.filter(lambda x: b not in x). And then call reduce(func, ...) instead. I'm guessing it had to do with scoping within anonymous functions, so naming it might help.

– Idlehands
Nov 14 '18 at 17:05















I thought that could be the issue indeed, but creating a function used only once is against my religion.

– Steven
Nov 14 '18 at 17:07





I thought that could be the issue indeed, but creating a function used only once is against my religion.

– Steven
Nov 14 '18 at 17:07




1




1





From my point of view, disposable named functions are evil! Well then you're lost! ...sorry

– Idlehands
Nov 14 '18 at 17:16







From my point of view, disposable named functions are evil! Well then you're lost! ...sorry

– Idlehands
Nov 14 '18 at 17:16














1 Answer
1






active

oldest

votes


















6














Most likely it's a bug in pylint.



Here is a similar bug report from 2 years ago




foo = lambda x: lambda: x + 1 print(foo(1)())



correctly prints 2 when run, but pylint incorrectly reports



E: 1,24: Undefined variable 'x' (undefined-variable)



This is a regression from pylint 1.4.x.




And here is a recent issue reporting the same issue on 11/14/2018




The issue has been reported at #760 and fixed by #2274. However, the
fix is merged only into pylint 2.x which supports only python >= 3.4
leaving us with the bug unresolved in the pylint 1.x series for python
2.




EDIT



Looks like your false positive might be slightly different than the issue above, nevertheless, I would still consider this a bug.



I would try creating an issue on their repo and see what happens
(if you decide to do so, please post link in comments so we can follow it.)






share|improve this answer

























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    1 Answer
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    1 Answer
    1






    active

    oldest

    votes









    active

    oldest

    votes






    active

    oldest

    votes









    6














    Most likely it's a bug in pylint.



    Here is a similar bug report from 2 years ago




    foo = lambda x: lambda: x + 1 print(foo(1)())



    correctly prints 2 when run, but pylint incorrectly reports



    E: 1,24: Undefined variable 'x' (undefined-variable)



    This is a regression from pylint 1.4.x.




    And here is a recent issue reporting the same issue on 11/14/2018




    The issue has been reported at #760 and fixed by #2274. However, the
    fix is merged only into pylint 2.x which supports only python >= 3.4
    leaving us with the bug unresolved in the pylint 1.x series for python
    2.




    EDIT



    Looks like your false positive might be slightly different than the issue above, nevertheless, I would still consider this a bug.



    I would try creating an issue on their repo and see what happens
    (if you decide to do so, please post link in comments so we can follow it.)






    share|improve this answer






























      6














      Most likely it's a bug in pylint.



      Here is a similar bug report from 2 years ago




      foo = lambda x: lambda: x + 1 print(foo(1)())



      correctly prints 2 when run, but pylint incorrectly reports



      E: 1,24: Undefined variable 'x' (undefined-variable)



      This is a regression from pylint 1.4.x.




      And here is a recent issue reporting the same issue on 11/14/2018




      The issue has been reported at #760 and fixed by #2274. However, the
      fix is merged only into pylint 2.x which supports only python >= 3.4
      leaving us with the bug unresolved in the pylint 1.x series for python
      2.




      EDIT



      Looks like your false positive might be slightly different than the issue above, nevertheless, I would still consider this a bug.



      I would try creating an issue on their repo and see what happens
      (if you decide to do so, please post link in comments so we can follow it.)






      share|improve this answer




























        6












        6








        6







        Most likely it's a bug in pylint.



        Here is a similar bug report from 2 years ago




        foo = lambda x: lambda: x + 1 print(foo(1)())



        correctly prints 2 when run, but pylint incorrectly reports



        E: 1,24: Undefined variable 'x' (undefined-variable)



        This is a regression from pylint 1.4.x.




        And here is a recent issue reporting the same issue on 11/14/2018




        The issue has been reported at #760 and fixed by #2274. However, the
        fix is merged only into pylint 2.x which supports only python >= 3.4
        leaving us with the bug unresolved in the pylint 1.x series for python
        2.




        EDIT



        Looks like your false positive might be slightly different than the issue above, nevertheless, I would still consider this a bug.



        I would try creating an issue on their repo and see what happens
        (if you decide to do so, please post link in comments so we can follow it.)






        share|improve this answer















        Most likely it's a bug in pylint.



        Here is a similar bug report from 2 years ago




        foo = lambda x: lambda: x + 1 print(foo(1)())



        correctly prints 2 when run, but pylint incorrectly reports



        E: 1,24: Undefined variable 'x' (undefined-variable)



        This is a regression from pylint 1.4.x.




        And here is a recent issue reporting the same issue on 11/14/2018




        The issue has been reported at #760 and fixed by #2274. However, the
        fix is merged only into pylint 2.x which supports only python >= 3.4
        leaving us with the bug unresolved in the pylint 1.x series for python
        2.




        EDIT



        Looks like your false positive might be slightly different than the issue above, nevertheless, I would still consider this a bug.



        I would try creating an issue on their repo and see what happens
        (if you decide to do so, please post link in comments so we can follow it.)







        share|improve this answer














        share|improve this answer



        share|improve this answer








        edited Nov 14 '18 at 16:57

























        answered Nov 14 '18 at 16:52









        gtalaricogtalarico

        1,124718




        1,124718
































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