Why Python 3.6.1 throws AttributeError: module 'enum' has no attribute 'IntFlag'?

Question

It's because your enum is not the standard library enum module. You probably have the package enum34 installed.

One way check if this is the case is to inspect the property enum.__file__

import enum
print(enum.__file__)  
# standard library location should be something like 
# /usr/local/lib/python3.6/enum.py

Since python 3.6 the enum34 library is no longer compatible with the standard library. The library is also unnecessary, so you can simply uninstall it.

pip uninstall -y enum34

If you need the code to run on python versions both <=3.4 and >3.4, you can try having enum-compat as a requirement. It only installs enum34 for older versions of python without the standard library enum.

Not sure whether you still have this issue. I had a similar issue and I was able to resolve it simply by unsetting PYTHONPATH

$ unset PYTHONPATH

For me this error occured after installing of gcloud component app-engine-python in order to integrate into pycharm. Uninstalling the module helped, even if pycharm is now not uploading to app-engine.

If anyone coming here because of getting this error while running a google app engine Python 3.7 standard environment project in PyCharm then all you need to do is

• Make sure the configuration to run is for Flask, not Google App Engine configuration.
• Then disable Google App Engine support under Preferences >> Languages & Framework >> Google App Engine

The reason being as per this link

The overall goal is that your app should be fully portable and run in any standard Python environment. You write a standard Python app, not an App Engine Python app. As part of this shift, you are no longer required to use proprietary App Engine APIs and services for your app's core functionality. At this time, App Engine APIs are not available in the Python 3.7 runtime.

I guess when we create a python 3.7 project in PyCharm as a Google app engine project it still tries to do the same way it does for a python2.7 app

DISCLAIMER: Please, @juanpa.arrivillaga, if you see this answer, feel free to write your own and I will remove this post.

@juanpa.arrivillaga had mentioned above:

Is there a file name enum.py in your working directory, by any chance?

This was the issue I encountered. I was not aware of the enum module on python at the time and had named my test file enum.py.

Since the file name is the module name, there was a conflict. More info on modules here: https://docs.python.org/2/tutorial/modules.html

Disabling "Google App Engine Support" in pycharm preferences fixed this issue for me.

Installing version 1.1.8 of enum34 worked for me.

I was able to fix this by adding enum34 = "==1.1.8" to pyproject.toml. Apparently enum34 had a feature in v1.1.8 that avoided this error, but this regressed in v1.1.9+. This is just a workaround though. The better solution would be for packages to use environment markers so you don't have to install enum34 at all unless needed.

Source: https://github.com/python-poetry/poetry/issues/1122