PytestCollectionWarning cannot collect because it is not a function

[briankosw]

Description:

In my model directory, I have a module named model.py, which contains a method called build_model(). In my test directory, I have a test directory model and a naturally a module named test_model.py, in which I have a test_build_model() method. I keep getting this particular warning:

../../../../../anaconda/envs/sukshiml/lib/python3.7/site-packages/tensorflow/python/keras/engine/base_layer.py:875
  /data/anaconda/envs/sukshiml/lib/python3.7/site-packages/tensorflow/python/keras/engine/base_layer.py:875: PytestCollectionWarning: cannot collect 'test_model' because it is not a function.
    def __call__(self, *args, **kwargs):

which I can only get rid of if I rename the test method from test_build_model() to test_model(), which is inconvenient and I don't want to see warnings that aren't actually warnings. I also get the same error for a couple other functions. How would I fix this behavior?

Package                   Version             Location
------------------------- ------------------- --------------------------------------------
absl-py                   0.10.0
alembic                   1.4.1
antlr4-python3-runtime    4.8
appdirs                   1.4.4
argon2-cffi               20.1.0
astunparse                1.6.3
async-generator           1.10
attrs                     20.2.0
azure-core                1.8.2
azure-storage-blob        12.5.0
backcall                  0.2.0
black                     20.8b1
bleach                    3.2.1
cachetools                4.1.1
certifi                   2020.6.20
cffi                      1.14.3
cfgv                      3.2.0
chardet                   3.0.4
click                     7.1.2
cloudpickle               1.6.0
coverage                  5.3
cryptography              3.1.1
databricks-cli            0.13.0
decorator                 4.4.2
defusedxml                0.6.0
distlib                   0.3.1
docker                    4.3.1
entrypoints               0.3
filelock                  3.0.12
flake8                    3.8.4
Flask                     1.1.2
gast                      0.3.3
gitdb                     4.0.5
GitPython                 3.1.11
google-auth               1.22.1
google-auth-oauthlib      0.4.1
google-pasta              0.2.0
gorilla                   0.3.0
greenlet                  0.4.16
grpcio                    1.32.0
gunicorn                  20.0.4
h5py                      2.10.0
hydra-core                1.0.3
identify                  1.5.6
idna                      2.10
importlib-metadata        2.0.0
importlib-resources       3.0.0
iniconfig                 1.1.1
ipykernel                 5.3.4
ipython                   7.18.1
ipython-genutils          0.2.0
isodate                   0.6.0
itsdangerous              1.1.0
jedi                      0.17.2
Jinja2                    2.11.2
jsonschema                3.2.0
jupyter-client            6.1.7
jupyter-core              4.6.3
jupyterlab-pygments       0.1.2
Keras-Preprocessing       1.1.2
Mako                      1.1.3
Markdown                  3.3.1
MarkupSafe                1.1.1
mccabe                    0.6.1
mistune                   0.8.4
mlflow                    1.11.0
msgpack                   1.0.0
msrest                    0.6.19
mypy-extensions           0.4.3
nbclient                  0.5.1
nbconvert                 6.0.7
nbformat                  5.0.8
nest-asyncio              1.4.1
nodeenv                   1.5.0
notebook                  6.1.4
numpy                     1.18.5
oauthlib                  3.1.0
omegaconf                 2.0.2
opt-einsum                3.3.0
packaging                 20.4
pandas                    1.1.3
pandocfilters             1.4.2
parso                     0.7.1
pathspec                  0.8.0
pexpect                   4.8.0
pickleshare               0.7.5
pip                       20.2.3
pluggy                    0.13.1
pre-commit                2.7.1
prometheus-client         0.8.0
prometheus-flask-exporter 0.18.1
prompt-toolkit            3.0.8
protobuf                  3.13.0
ptyprocess                0.6.0
py                        1.9.0
pyasn1                    0.4.8
pyasn1-modules            0.2.8
pycodestyle               2.6.0
pycparser                 2.20
pyflakes                  2.2.0
Pygments                  2.7.1
pynvim                    0.4.1
pyparsing                 2.4.7
pyrsistent                0.17.3
pytest                    6.1.1
pytest-cov                2.10.1
python-dateutil           2.8.1
python-editor             1.0.4
pytz                      2020.1
PyYAML                    5.3.1
pyzmq                     19.0.2
querystring-parser        1.2.4
regex                     2020.10.15
requests                  2.24.0
requests-oauthlib         1.3.0
rsa                       4.6
Send2Trash                1.5.0
setuptools                50.3.0.post20201006
six                       1.15.0
smmap                     3.0.4
SQLAlchemy                1.3.13
sqlparse                  0.4.1     
tabulate                  0.8.7
tensorboard               2.3.0
tensorboard-plugin-wit    1.7.0
tensorflow                2.3.1
tensorflow-estimator      2.3.0
termcolor                 1.1.0
terminado                 0.9.1
testpath                  0.4.4
toml                      0.10.1
tornado                   6.0.4
traitlets                 5.0.5
typed-ast                 1.4.1
typing-extensions         3.7.4.3
urllib3                   1.25.11
virtualenv                20.0.35
wcwidth                   0.2.5
webencodings              0.5.1
websocket-client          0.57.0
Werkzeug                  1.0.1
wheel                     0.35.1
wrapt                     1.12.1
zipp                      3.3.1

[nicoddemus]

Hi @briankosw,

TBH I don't follow what's happening precisely...

In my model directory, I have a module named model.py, which contains a method called build_model(). In my test directory, I have a test directory model and a naturally a module named test_model.py, in which I have a test_build_model() method.

Fine so far.

I keep getting this particular warning:

But here I get a bit lost, you get a warning from base_layer.py:875 (not mentioned until now) about test_model (also not mentioned until now) not being a function.

Which I can only get rid of if I rename the test method from test_build_model() to test_model(),

But the message above mentions test_model, not test_build_model... and anyway both of them have the prefix test_ which pytest uses to consider test functions, so I'm at a loss why there's a difference.

---

Regardless a few hints that might help:

1. You can add a __test__ = False attribute to any object to have pytest ignoring it even if it would normally consider that object a test.
2. You can ignore warnings using the filterwarnings configuration option.

Hope this helps!

[briankosw]

Hey @nicoddemus,

The base_layer.py:875 is from TensorFlow's code, not mine, which adds to my confusion. test_model is the name of the test method for build_model. If I rename the test method from test_model to test_build_model, then the warning goes away. Hopefully that might be enough context, but otherwise I will try your hints!