How to fix ModuleNotFoundError: No module named 'grpc' in Python

Problem:

You want to run a Python script that is using some Google Cloud services. However you see an error message similar to this:

[...]
  File "/usr/local/lib/python3.6/dist-packages/google/api_core/gapic_v1/__init__.py", line 16, in <module>
    from google.api_core.gapic_v1 import config
  File "/usr/local/lib/python3.6/dist-packages/google/api_core/gapic_v1/config.py", line 23, in <module>
    import grpc
ModuleNotFoundError: No module named 'grpc'

Solution

Install the grpcio Python module:

sudo pip3 install grpcio

or, for Python 2.x

sudo pip install grpcio