Python Flask import Error of module that isn´t being imported

Question

I have a flask app running in Google App Engine. Yesterday, I deployed a new version of my app where I only change the HTML style. It deployed as it was supposed to. Today, I realized that I didn't change the title for each corresponding HTML page, so I only changed the title tag in each HTML page. I deployed the app again and now I'm getting this strange error of an Import Error for a module that I have never even used. How can I fix this?

The error:

ImportError: cannot import name 'json' from 'itsdangerous' (/layers/google.python.pip/pip/lib/python3.7/site-packages/itsdangerous/__init__.py)

EDIT FEB 24, 2022:

as you can see, the original folder to python3.7 has been replaced with python3.9

Is this normal in GAE?

score 6 · Answer 1 · edited Feb 18 '22 at 22:00

6

This issue on Flask's GitHub is related.

Either update to Flask>2, or if that's not possible pin ItsDangerous<2 and MarkupSafe<2.

To pin to lower versions in a requirements.txt file:

flask==1.1.4
itsdangerous==1.1.0
markupsafe==1.1.1

edited Feb 18 '22 at 22:00

davidism

121,510
29
395
339

answered Feb 18 '22 at 17:23

John McCabe

702
1
6
16

thank you! What had happend also was the that in the traceback, the directory says python3.7 which is the version I have always used. When I search the folder for python 3.7, Google App Engine last night had replaced it with python3.9....do you know if this always happens like this without warning? – santiagoorpi Feb 18 '22 at 20:55
Do you mean that the version of your App Engine service changed? It shouldn't as the runtime is [defined](https://cloud.google.com/appengine/docs/standard/python3/configuring-your-app-with-app-yaml) on `runtime` configuration item from the `app.yaml` file. – Emmanuel Feb 22 '22 at 14:58
yes sir it did....the app.yaml had not changed from its original 3.7 as i had left it.....but python version 3.7 was no longer in my cloud shell....there is only 2 folders...one that says Python2.7 and Python3.9....really weird :( – santiagoorpi Feb 24 '22 at 20:42
if this happens again I suggest to write the details it on another post on Stack or even report it on [Googles issue tracker](http://issuetracker.google.com/) – Emmanuel Feb 28 '22 at 14:59
Thank you!! I was pulling my hair out about this error! – Jim In Texas Apr 22 '22 at 21:59

score 4 · Answer 2 · answered Feb 18 '22 at 16:31

4

I had the same issue today. I was using flask=1.1.2, and when I updated the version to flask==2.0.3, the import issue was resolved.

answered Feb 18 '22 at 16:31

Elliot Henry

65
6

I tried this and in fact worked for fixing the issue originally stated. But later in my code I had an operation with `.__dict__` property. Broke there because keys are not the same as in 1.1.2. For making things work without changing my code for the moment, stick to keep using `flask=1.1.2` and added these to requirements.txt: `itsdangerous==1.1.0` `markupsafe==1.1.1`. – Jose Rondon Feb 21 '22 at 10:42

score 3 · Answer 3 · edited Feb 18 '22 at 21:59

3

This is caused by changes in Flask dependencies. Another question about this was asked on ServerFault.

You can either upgrade to Flask>2, or I had to downgrade to itsdangerous==2.0.1 if you can't do that.

edited Feb 18 '22 at 21:59

davidism

121,510
29
395
339

answered Feb 18 '22 at 16:15

new name

15,861
19
68
114

score 1 · Answer 4 · answered Feb 23 '22 at 16:29

1

the deprecation is performed with itsdangerous > 2.0.1.

answered Feb 23 '22 at 16:29

khancell

329
2
4

Python Flask import Error of module that isn´t being imported

4 Answers4

Linked