False positive ``abstract-class-instantiated`` with ``pandas.ExcelWriter``

[mhooreman]

Hello,

Steps to reproduce

Run pylint on the following code:

"""Lorem ipsum"""

import pandas as pd

def demo():
    """Demo for the false positive"""
    with pd.ExcelWriter("demo.xlsx") as writer:
        print(writer)

Current behavior

Pylint gives: abstract-class-instantiated(E0110): test.py:8:9: demo: Abstract class 'ExcelWriter' with abstract methods instantiated

Expected behavior

No issue

pylint --version output

• Astroid 2.2.5
• Pylint 2.3.1
• Python 3.7.4
• GCC 7.4.0

Discussion

This ticket has originally been opened on pandas github: https://github.com/pandas-dev/pandas/issues/27634

According to the discussions there, it seems that pylint has issues with introspection of objects defining __new__

[dasrequiem]

I just ran into this exact issue.

[PCManticore]

Thanks for the report folks!

[mhooreman]

You're welcome. Thanks for your help.

Le ven. 16 août 2019 17:22, Claudiu Popa notifications@github.com a écrit :

Thanks for the report folks!

— You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub https://github.com/PyCQA/pylint/issues/3060?email_source=notifications&email_token=ABYIHFTFNBN6FLJGJPQ6LQTQE3A4DA5CNFSM4ILLMDY2YY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGOD4O5E4Y#issuecomment-522048115, or mute the thread https://github.com/notifications/unsubscribe-auth/ABYIHFXN7REEB5LVEZYNEFDQE3A4DANCNFSM4ILLMDYQ .

[lleeoo]

To save y'all 10s here is the comment line to temporarily disable this error and point to this page: # https://github.com/PyCQA/pylint/issues/3060 pylint: disable=abstract-class-instantiated

[gk2go]

+1

[drdDavi]

Guys, this is driving me mad, could someone please tell me how to implement a temporary fix.

[EdgarOrtegaRamirez]

@UrAvgDeveloper this is what I did to disable this check globally, you need a .pylintrc file, look for [MESSAGES CONTROL] then for disable= and add abstract-class-instantiated

[usser123]

I encountered the same issue.

I get a pylint message on the line: writer = pd.ExcelWriter(output, engine='xlsxwriter')

'Abstract class ExcelWriter with abstract methods instantiated'

pandas==0.25.3

[liamsuma]

same issue as of today writer = pd.ExcelWriter('path to file') 'Abstract class 'ExcelWriter' with abstract methods instantiated'

[grishagin]

Same here. Used the following syntax as a temporary fix: with pd.ExcelWriter(outfile_name) as xl_writer: #pylint: disable=abstract-class-instantiated

[Svestis]

Same as of today: (abstract-class-instantiated)Abstract class 'ExcelWriter' with abstract methods instantiated

[acamposc]

+1 Abstract class 'ExcelWriter' with abstract methods instantiatedpylint(abstract-class-instantiated)

[MattSom]

For me as well: Abstract class 'ExcelWriter' with abstract methods instantiated

[ffanderson]

Me too :(

[ffanderson]

with pd.ExcelWriter(outfile_name) as xl_writer: #pylint: disable=abstract-class-instantiated

Doesn't this just thrown a line length error?

[grishagin]

with pd.ExcelWriter(outfile_name) as xl_writer: #pylint: disable=abstract-class-instantiated

Doesn't this just thrown a line length error?

Not in my case... I didn't change any of the pylint's defaults.
In any case, one can adjust that setting: https://stackoverflow.com/questions/52058886/visual-studio-code-with-pylint-and-autopep8-how-can-i-avoid-pylint-to-complain

[aaronsmith1234]

I am still getting this on v2.12.2; not sure why! Same code, pandas.ExcelWriter

[clavedeluna]

@DanielNoord I started to look at this issue and I'm not totally convinced this is an astroid issue. The same thing can be reproduced with:

import abc

class Test(metaclass=abc.ABCMeta):
    def __new__(cls):
        pass

    @property
    @abc.abstractmethod
    def sheets(self):
        """Mapping of sheet names to sheet objects."""

    @property
    @abc.abstractmethod
    def book(self):
        """
        Book instance. Class type will depend on the engine used.
        This attribute can be used to access engine-specific features.
        """

test = Test()

and also without __new__ in the definition. In fact, the functional tests hint that raising this message is expected.

So is there something specific for pandas that needs to be done in astroid, or can we do something in pylint's _check_inferred_class_is_abstract to nope out if a __new__ method is defined? Just throwing ideas....

[DanielNoord]

Good find, although the check can't be that simple sadly. Consider:

import abc

class Test(metaclass=abc.ABCMeta):
    def __new__(cls):
        print("Test.__new__")
        return super().__new__(cls)

    @property
    @abc.abstractmethod
    def sheets(self):
        """Mapping of sheet names to sheet objects."""

    @property
    @abc.abstractmethod
    def book(self):
        """
        Book instance. Class type will depend on the engine used.
        This attribute can be used to access engine-specific features.
        """

test = Test()

Anyway, this is indeed something that should be fixed in pylint.

[clavedeluna]

So is the idea to fix this issue to not raise abstract-class-instantiated in the case the class has an implemented __new__ method?

[DanielNoord]

No, we should not raise it if there wouldn't be an exception raised. In the example I gave the code would still crash, so the message is valid.,

[mhooreman]

Hi Any update on this? I still have the issue with pd 2.0.2 Thanks