Edward2 backend

[hussienalbared]

I am facing this issue although both tensorflow and numpy are installed

raise ImportError("No backend is available for Edward2. Please install "
ImportError: No backend is available for Edward2. Please install dependencies for JAX, NumPy, or TensorFlow.

numpy 1.23.5
scipy 1.11.2
tb-nightly 2.15.0a20230919
tensorboard 2.14.0
tensorflow 2.14.0rc1
tensorflow-probability 0.21.0
termcolor 2.3.0
tf-estimator-nightly 2.14.0.dev2023080308
tf-nightly 2.15.0.dev20230920

[arthur-thuy]

I'm encountering the same issue, but only when installing the latest development version of edward2 (version 0.0.3) with:

pip install "git+https://github.com/google/edward2.git#egg=edward2"

When I install the 0.0.2 version with pypi (pip install edward2), it finds the backend. However, I get a different error related to scipy which was fixed in commit d23eddd (after the release of 0.0.2).

[arthur-thuy]

For version 0.0.2, closed issue #566 proposes to use pip install scipy==1.7.3. This works for me.

Obviously, this doesn't change anything for the backend problem with 0.0.3.

[phanav]

The cause was a missing package for me (tenacity).

I found out by editing this file in the installation path:

/miniconda3/envs/tf2/lib/python3.10/site-packages/edward2/__init__.py
Then, catch and print the exception.

try:
  from edward2 import jax
  __all__ += ["jax"]
except (ImportError, AttributeError) as exc:
  # We also catch AttributeError. JAX can raise AttributeError during
  # imports in colab unless JAX is directly installed first.
  print(exc)
  warnings.warn("JAX backend for Edward2 is not available.")

(No module named tenacity)

Finally, install the missing package.