对于tensorflow GPU训练下Function call stack: train_function 问题的解决（.fit_generator callback）
一、错误记录：
callbacks = callbacks_list#callbacks_list
File "C:\Users\123\anaconda3\envs\py37\lib\site-packages\tensorflow\python\util\deprecation.py", line 324, in new_func
return func(*args, **kwargs)
File "C:\Users\123\anaconda3\envs\py37\lib\site-packages\tensorflow\python\keras\engine\training.py", line 1479, in fit_generator
initial_epoch=initial_epoch)
File "C:\Users\123\anaconda3\envs\py37\lib\site-packages\tensorflow\python\keras\engine\training.py", line 66, in _method_wrapper
return method(self, *args, **kwargs)
File "C:\Users\123\anaconda3\envs\py37\lib\site-packages\tensorflow\python\keras\engine\training.py", line 848, in fit
tmp_logs = train_function(iterator)
File "C:\Users\123\anaconda3\envs\py37\lib\site-packages\tensorflow\python\eager\def_function.py", line 580, in __call__
result = self._call(*args, **kwds)
File "C:\Users\123\anaconda3\envs\py37\lib\site-packages\tensorflow\python\eager\def_function.py", line 644, in _call
return self._stateless_fn(*args, **kwds)
File "C:\Users\123\anaconda3\envs\py37\lib\site-packages\tensorflow\python\eager\function.py", line 2420, in __call__
return graph_function._filtered_call(args, kwargs) # pylint: disable=protected-access
File "C:\Users\123\anaconda3\envs\py37\lib\site-packages\tensorflow\python\eager\function.py", line 1665, in _filtered_call
self.captured_inputs)
File "C:\Users\123\anaconda3\envs\py37\lib\site-packages\tensorflow\python\eager\function.py", line 1746, in _call_flat
ctx, args, cancellation_manager=cancellation_manager))
File "C:\Users\123\anaconda3\envs\py37\lib\site-packages\tensorflow\python\eager\function.py", line 598, in call
ctx=ctx)
File "C:\Users\123\anaconda3\envs\py37\lib\site-packages\tensorflow\python\eager\execute.py", line 60, in quick_execute
inputs, attrs, num_outputs)
tensorflow.python.framework.errors_impl.UnimplementedError: Cast string to float is not supported
[[node model/Cast (defined at train.py:306) ]] [Op:__inference_train_function_30543]
Function call stack:
train_function
二、解决方案
参照：https://stackoverflow.com/questions/61304463/issue-with-keras-fit-generator-epoch
在使用cpu训练时没有问题，使用gpu时出现Function call stack:
train_function 本来以为是传参错误，
按照回溯检查了
ModelCheckpoint, EarlyStopping, ReduceLROnPlateau.fit_generator （ callback） 没有找出问题
在stackoverflow上大神们的启发下
发现是在tensorflow2.x下调用tf.combat1没有关闭eager_execution()
按照上面给出的第三点
加入
tf.compat.v1.disable_eager_execution()
运行成功！
附录：pip list
Package Version
------------------------ ------------
-ensorflow-gpu 2.2.0
absl-py 0.9.0
astor 0.8.1
astunparse 1.6.3
attr 0.3.1
attrs 19.3.0
bleach 1.5.0
cachetools 4.1.1
certifi 2020.6.20
chardet 3.0.4
coremltools 4.0b1
cycler 0.10.0
gast 0.3.3
google-auth 1.18.0
google-auth-oauthlib 0.4.1
google-pasta 0.2.0
grpcio 1.30.0
h5py 2.10.0
html5lib 0.9999999
idna 2.10
importlib-metadata 1.7.0
joblib 0.14.1
Keras 2.4.3
Keras-Applications 1.0.8
Keras-Preprocessing 1.1.2
kiwisolver 1.1.0
Markdown 3.2.2
matplotlib 3.0.3
mock 4.0.2
mpmath 1.1.0
numpy 1.19.0
oauthlib 3.1.0
opt-einsum 3.2.1
pandas 1.0.5
Pillow 7.2.0
pip 20.1.1
protobuf 3.12.2
pyasn1 0.4.8
pyasn1-modules 0.2.8
pyparsing 2.4.7
python-dateutil 2.8.1
pytz 2020.1
PyYAML 5.3.1
requests 2.24.0
requests-oauthlib 1.3.0
rsa 4.6
scikit-learn 0.22.2.post1
scipy 1.4.1
seaborn 0.9.1
setuptools 49.1.2
six 1.15.0
sklearn 0.0
sympy 1.6.1
tensorboard 2.2.2
tensorboard-plugin-wit 1.7.0
tensorflow-estimator 1.15.1
tensorflow-gpu 2.2.0
tensorflow-gpu-estimator 2.2.0
termcolor 1.1.0
Theano 1.0.4
tqdm 4.47.0
urllib3 1.25.9
webencodings 0.5.1
Werkzeug 1.0.1
wheel 0.29.0
wincertstore 0.2
wrapt 1.12.1
zipp 1.2.0