Using google-cloud-aiplatform alongside google-cloud-bigquery causes google.cloud.bigquery imports to fail mypy

[SanRehmo]

Bug Report

I'm having an issue where using google-cloud-aiplatform andgoogle-cloud-bigquery in the same project causes google.cloud.bigquery imports to fail mypy.
This is similar to #10360 but caused by a different package.

To Reproduce

With three .py files with the following imports:

script_one.py:

import logging
from google.cloud import bigquery

script_two.py:

import json
import logging

import click
import google
from google.cloud import bigquery

script_three.py:

from google.cloud.aiplatform_v1beta1 import (
    FeaturestoreOnlineServingServiceClient,
    FeaturestoreServiceClient,
)
from google.cloud.aiplatform_v1beta1.services.featurestore_service import (
    FeaturestoreServiceAsyncClient,
)
from google.cloud.aiplatform_v1beta1.types import (
    BigQuerySource,
    FeatureSelector,
    IdMatcher,
    featurestore,
    featurestore_online_service,
    featurestore_service,
)

as well as the requirements.txt file

grpcio==1.40.0
prometheus-client==0.11.0
py-grpc-prometheus==0.7.0
google-cloud-bigquery==2.26.0
google-cloud-aiplatform==1.4.3
ddtrace==0.51.2
pytz~=2021.1
types-pytz~=2021.1.2

Actual Behavior

I get the following errors when running mypy:

script_one.py:6: error: Module "google.cloud" has no attribute "bigquery"
script_two.py:6: error: Module "google.cloud" has no attribute "bigquery"

Changing the import from from google.cloud import bigquery to import google.cloud.bigquery as bigquery as proposed in #10360 (comment) in any one of script_one.py or script_two.py fixes the issue for both of them.

Also, removing all google-cloud-aiplatform imports form script_three.py fixes the issue.

Expected Behavior

I would not expect the usage of one package (google-cloud-aiplatform) to influence the mypy checks of another (google-cloud-bigquery).

Your Environment

• Mypy version used: 0.910
• Mypy command-line flags: mypy
• Mypy configuration options from mypy.ini (and other config files): None
• Python version used: 3.8.5
• Operating system and version: CentOS 7.6

[hauntsaninja]

Does using --namespace-packages fix?

[SanRehmo]

Does using --namespace-packages fix?

Yes it does, however this causes another errors to appear:

a/b/__init__.py: error: Source file found twice under different module names: "a" and "a.b"

[hauntsaninja]

Okay, https://mypy.readthedocs.io/en/stable/running_mypy.html#mapping-file-paths-to-modules can help you fix that.