CODEWITHSUNDEEP
pythonpython-3.xsqlalchemyflask-sqlalchemypylint
Pedro Teixeira
Pedro Teixeira

Reputation: 649

Pylint can't find SQLAlchemy query member

I have a Flask (v0.10.1) application using Flask-SQLAlchemy (v2.0) and I'm trying to configure Pylint to check it. Running with Python 3.4.2.

First error was:

 Instance of 'SQLAlchemy' has no 'Table' member (no-member)

And I fixed this one ignoring the check for member attributes on SQLAlchemy:

ignored-classes=SQLAlchemy

But I'm having a problem with the query member on entities:

Class 'UserToken' has no 'query' member (no-member)

Is there any way to fix this issue without having to ignore no-member errors on every query call?

Flask bootstrap:

from flask import Flask
from flask_sqlalchemy import SQLAlchemy

db = SQLAlchemy()
app = Flask(__name__)
db.init_app(app)
app.run()

UserToken entity:

from app import db

class UserToken(db.Model):
    user_token_id = db.Column(db.Integer, primary_key=True, index=True)
    token_auth = db.Column(db.String(64), unique=True, nullable=False, index=True)

The controller:

from entities import UserToken

token = UserToken.query.filter(
    UserToken.token_auth == token_hash,
).first()

Upvotes: 64

Views: 48369

Answers (14)

Tai Lu
Tai Lu

Reputation: 43

Here is 2022.

My solution:

pip install pylint-flask-sqlalchemy

For VSCode (v2022.2.0), add below lines on .vscode/settings.json:

  "pylint.args": [
    "--load-plugins",
    "pylint_flask_sqlalchemy"
  ]

For terminal

pylint --load-plugins pylint_flask_sqlalchemy /path/{folder/file}
``

Upvotes: 2

user
user

Reputation: 1240

Solution

pip install pylint-flask

pip install pylint-flask-sqlalchemy

Load the installed plugin.

For example, if you use VS code, please edit settings.json file as follows:

"python.linting.pylintArgs": ["--load-plugins", "pylint_flask_sqlalchemy", "pylint_flask"]

Optional

If having other warnings, define remaining members in generated-members in pylintrc file.

Upvotes: 62

Niko Fohr
Niko Fohr

Reputation: 33770

Warning: Do not just --load-plugins pylint-flask

  • By doing this (using dashes instead of underscores) you will just disable pylint altogether! This is because the --load-plugins needs the name of the python package to be imported. You can check this on command line (will get ImportError) if you do so. Pylinting in VS Code is nastier since you will not get any visible errors. Instead, you will have zero linting errors even if your code would have some linting problems.

pylint-flask will not work

pylint-flask is a good plugin, but it is not even meant to tackle this problem! You can see the source code for yourself. There is no mentions about Flask-SQLAlchemy; it is only designed to fix issues (false positives) with Flask.

pylint-flask-sqlalchemy

The pylint-flask-sqlalchemy was created to fix the pylint false positives with Flask-SQLAlchemy. After installing with

pip install pylint-flask-sqlalchemy

one should add it with1

# NOT: "pylint-flask-sqlalchemy"
"python.linting.pylintArgs": ["--load-plugins", "pylint_flask_sqlalchemy"]

1Applies directly only for VS Code. With other IDEs or command line, use the same arguments in the same order.

pylint-flask with pylint-flask-sqlalchemy

If used together, for some reason

"python.linting.pylintArgs": ["--load-plugins", "pylint_flask", "pylint_flask_sqlalchemy"]

will not work but

"python.linting.pylintArgs": ["--load-plugins", "pylint_flask_sqlalchemy", "pylint_flask"]

does. So, presumably, the pylint-flask must be loaded after pylint-flask-sqlalchemy.

Upvotes: 12

Suchit Borge
Suchit Borge

Reputation: 11

The one that worked for me was switching to flake8 python linter. Below are the steps:

  1. Open VSCode and run Ctrl+Shift+P (for Windows Users)

  2. In the VSCode Search prompt, type Python:Select Linter. You will see a list of all Linters and select flake8.

  3. If you do not have flake8 installed as a VScode extension for pylint, it will prompt you to install it. Proceed and install it.

Upvotes: 1

Saravana Kumar
Saravana Kumar

Reputation: 85

In the first solution in this page, following needs to be updated. Its a typo issue,

Instead of "pylint_flask" in this settings.json parameter(in this line: "python.linting.pylintArgs": ["--load-plugins", "pylint_flask"]) it should be "python.linting.pylintArgs": ["--load-plugins", "pylint-flask"]).

Upvotes: 5

Martin
Martin

Reputation: 281

Use pylint plugin pylint-flask-sqlalchemy

pip install pylint_flask_sqlalchemy

And in your settings.json of VisualCode

"python.linting.pylintArgs": ["--load-plugins", "pylint_flask_sqlalcheny"]

Upvotes: 8

Emz Amechu
Emz Amechu

Reputation: 99

The one that worked for me was switching to flake8 python linter. Below are the steps:

  1. Open VSCode and run Ctrl+shift+P(For Windows Users)
  2. In the VSCode Search prompt, type Python:Select Linter. You will see a list of all Linters and select flake8.
  3. If you do not have flake8 installed as a VScode extension for pylint, it will prompt you to install it. Proceed and install it.

Upvotes: 9

axis
axis

Reputation: 301

I meet the same issue when using flask_sqlalchemy. my solution is: 

pylint --generate-rcfile>~/.config/pylintrc

and then find the

ignored-modules

line, rewrite it to:

ignored-modules=flask_sqlalchemy

all E1101 errors are gone.

Remeber to read the comment:

# List of module names for which member attributes should not be checked
# (useful for modules/projects where namespaces are manipulated during runtime
# and thus existing member attributes cannot be deduced by static analysis. It
# supports qualified module names, as well as Unix pattern matching.

Upvotes: 20

dondrzzy
dondrzzy

Reputation: 300

After trying a lot of these options, plugins and adding query and all. The only solution that erased those scoped_session errors was using:

  1. pylint --generate-rcfile > pylintrc
  2. look for the ignored_classes and add scoped_session after the comma, leave no space
  3. Run pylint on your module again.

Upvotes: 7

Kurtiss Hare
Kurtiss Hare

Reputation: 61

Here's a version of joeforker's answer that dynamically adds all public methods from the Session object back into a scoped_session's locals at lint-time, instead of hardcoding a few well-known method names.

Define {path}/{to}/pylintplugins.py:

import sys

from astroid import MANAGER, scoped_nodes
from astroid.builder import AstroidBuilder
from sqlalchemy.orm import Session


def register(_linter):
    pass

def transform(cls):
    if cls.name == 'scoped_session':
        builder = AstroidBuilder(MANAGER)
        module_node = builder.module_build(sys.modules[Session.__module__])
        session_cls_node = [
            c for c in module_node.get_children()
            if getattr(c, "type", None) == "class" and c.name == Session.__name__
        ][0]

        for prop in Session.public_methods:
            cls.locals[prop] = [
                c for c in session_cls_node.get_children() 
                if getattr(c, "type", None) == "method" and c.name == prop
            ]

MANAGER.register_transform(scoped_nodes.Class, transform)

And in your .pylintrc file:

load-plugins={path}.{to}.pylintplugins

Upvotes: 6

jojonas
jojonas

Reputation: 1675

Another alternative is to add scoped_session to the list of ignored classes:

# List of class names for which member attributes should not be checked (useful
# for classes with dynamically set attributes). This supports the use of
# qualified names.
ignored-classes=scoped_session

Upvotes: 2

joeforker
joeforker

Reputation: 41747

This is how I'm dealing with the issue for scoped_session. Trivial to extend to check for more cls names with SQLAlchemy attributes.

from astroid import MANAGER
from astroid import scoped_nodes

def register(_linter):
    pass

def transform(cls):
    if cls.name == 'scoped_session':
        for prop in ['add', 'delete', 'query', 'commit', 'rollback']:
            cls.locals[prop] = [scoped_nodes.Function(prop, None)]

MANAGER.register_transform(scoped_nodes.Class, transform)

Adapted from https://docs.pylint.org/en/1.6.0/plugins.html . Then make sure pylint loads your plugin.

pylint -E --load-plugins warning_plugin Lib/warnings.py

(or load it in pylintrc)

Upvotes: 0

0rkan
0rkan

Reputation: 843

Any class you declare as inheriting from db.Model won't have query member until the code runs so Pylint can't detect it.

The workaround for this besides ignoring no-member errors on every query call is to add query on the generated-members list in a Pylint config file since it is a member that will only be created at runtime.

When you run Pylint, it will search for a configuration file as stated in its documentation:

You can specify a configuration file on the command line using the --rcfile option. Otherwise, Pylint searches for a configuration file in the following order and uses the first one it finds:

  1. pylintrc in the current working directory
  2. If the current working directory is in a Python module, Pylint searches up the hierarchy of Python modules until it finds a pylintrc file. This allows you to specify coding standards on a module-by-module basis. Of course, a directory is judged to be a Python module if it contains an __init__.py file
  3. The file named by environment variable PYLINTRC
  4. if you have a home directory which isn’t /root:
    1. .pylintrc in your home directory
    2. .config/pylintrc in your home directory
  5. /etc/pylintrc

So if you don't have a config and you want a system wide default config for pylint you can use pylint --generate-rcfile > /etc/pylintrc. This will generate a commented configuration file according to the current configuration (or the default if you don't have one) that you can edit to your preferences.

p.s.: generated-members on a config file is the right way to deal with this warning, as it's said by the commented config 

  # List of members which are set dynamically and missed by pylint inference
  # system, and so shouldn't trigger E0201 when accessed. Python regular
  # expressions are accepted.

Upvotes: 23

Pedro Teixeira
Pedro Teixeira

Reputation: 649

After a lot of investigation I was not able to make Pylint to understand this member, so I just added query to the generated-members list and the check is ignored.

It's not a perfect solution but it works.

Upvotes: 0

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