Recently I tried to deploy my django app in google app engine (standard environment - Python version 3.7 - Django version 2.0.3) but I found a problem.
As a previous step to do the deploy I run:
pip freeze > requirements.txt
But at the time of deploy this error was generated:
Error message: `pip_download_wheels` had stderr output:
Failed building wheel for PyYAML
ERROR: Failed to build one or more wheels
error: `pip_download_wheels` returned code: 1.
When I realized that the error was due to PyYAML I tried to modify the version in the requirements.txt file, but it didn't work.
As last step I opted to remove PyYAML from my requirements.txt file and in this case it worked. The application is deployed and working.
However my question is: Is there a problem with having deployed without including PyYAML in the requirements.txt?
For those who might be interested, the answer is this:
Google app Engine (standard environment) does not allow to install PyYaml since by default it has it installed:
https://cloud.google.com/appengine/docs/standard/python/refdocs/
Therefore there is no problem with not add PyYaml in the requirements.txt
PD: it seems that the library PyYaml is added to requirements.txt file due to the fact that pip is recognizing the yaml file in the folders and determines that it is necessary for the application to work correctly.