Keras: TypeError: 'NoneType' object is not callable

[ishihiroki]

My environment

python 3.5.2 anaconda (use pyenv)
keras 2.3.0
tensorflow 1.4.1
theano 1.0.1
cntk 2.3

When backend is tensorflow, TypeError occurs just before learning is finished.

TypeError: 'NoneType' object is not callable

Is there a solution?

[ishihiroki]

I'm sorry...

keras version is 2.1.3

[pavithrasv]

Can you please share a standalone code snippet that can help reproduce the problem?

[chethh]

Same problem happens using github/keras/examples/neural_doodle.py.

[chethh]

Using latest nvidia, cuda 9.0, tensorflow 1.5, keras installed by current pip3.

[AlexanderKUA]

The same issue with Ubuntu native Python3(v3.5.2), Keras(v2.1.5) and Tensorflow(v1.6.0).
Traceback is below:

Exception ignored in: <bound method BaseSession.__del__ of <tensorflow.python.client.session.Session object at 0x7f8a8c2b1f98>>
Traceback (most recent call last):
  File "/usr/local/lib/python3.5/dist-packages/tensorflow/python/client/session.py", line 712, in __del__
TypeError: 'NoneType' object is not callable

[hfawaz]

same issue

[noirmist]

I had the same issue. But I tried it again, and it is working fine. It's weird.

[alexlao]

I've been getting this issue as well. It only happens sometimes. It's unfortunate for it to happen after a long training session, as this prevents me from being able to save my models.

[YunheFeng]

the same issue on tensorflow:1.7.1-devel-gup-py3 docker tags. Sometimes it works, while sometimes the issue occurs.

[xiaohk]

Same issue

[tgamauf]

Same here.

Python 3.5.2
Keras 2.1.5
Tensorflow 1.7

[AsimSaif001]

same issue
python 3.5
keras 2.1

[nguyenvulong]

same here
python 3.5.2
tensorflow 1.10.1 (with built-in keras)
pip 18.0

[kk2491]

As a workaround you can fix the error by writing the below 2 lines of code at the end of training code.

import gc
gc.collect()

[morpheusthewhite]

Same here
python 3.5
tensorflow 1.10
keras 2.2.4

[clappis]

I had the same issue. In my case, delete the __pycache__ was a workaround.
rm -rf /usr/lib/{PYTHON_VERSION}/__pycache__/

[supratik-bhattacharya-2020]

Same here
python 3.6.9
tensorflow 1.9