python3.7 -m pip install --upgrade https://storage.googleapis.com/tensorflow/mac/cpu/tensorflow-0.12.0-py3-none-any.whl
  wget https://raw.githubusercontent.com/aymericdamien/TensorFlow-Examples/master/examples/1_Introduction/helloworld.py
  python3.7 helloword.py

Tensorflow 0.12, released over two years (before 3.7 development had even started) runs fine.

Probably a C extension that needs to be compiled against a new version. Unlikely it is an actual compatibility break.