added and upgraded the python packages on Dimitris message

torch 1.7.0a0 requires dataclasses, which is not installed.
tensorboard 2.3.0 requires tensorboard-plugin-wit, which is not installed.
pyrdf 0.2.1 requires enum34, which is not installed.
caniusepython3 7.1.0 requires argparse, which is not installed.
pyspark 3.0.1 has requirement py4j==0.10.9, but you have py4j 0.10.7.
tensorflow-cpu 2.3.0 has requirement gast==0.3.3, but you have gast 0.2.2.
tensorflow-cpu 2.3.0 has requirement h5py<2.11.0,>=2.10.0, but you have h5py 2.9.0.
tensorflow-cpu 2.3.0 has requirement keras-preprocessing<1.2,>=1.1.1, but you have keras-preprocessing 1.1.0.    
tensorflow-cpu 2.3.0 has requirement protobuf>=3.9.2, but you have protobuf 3.8.0.
tensorflow-cpu 2.3.0 has requirement scipy==1.4.1, but you have scipy 1.5.1.
pytest 0.0.0 has requirement py>=1.8.2, but you have py 1.5.4.
multiprocess 0.70.10 has requirement dill>=0.3.2, but you have dill 0.3.1.dev0.
itkwidgets 0.32.0 has requirement ipywidgets>=7.5.1, but you have ipywidgets 7.4.2.
ipympl 0.4.1 has requirement ipywidgets>=7.5.0, but you have ipywidgets 7.4.2.
hepdata-converter 0.2.3 has requirement pyyaml>=5.3, but you have pyyaml 5.1.
distributed 1.28.1 has requirement dask>=0.18.0, but you have dask 0+unknown.