I am trying to get a Flask and Docker application to work but when I try and run it using my
docker-compose up command in my Visual Studio terminal, it gives me an ImportError called
ImportError: cannot import name 'json' from itsdangerous. I have tried to look for possible solutions to this problem but as of right now there are not many on here or anywhere else. The only two solutions I could find are to change the current installation of MarkupSafe and itsdangerous to a higher version: https://serverfault.com/questions/1094062/from-itsdangerous-import-json-as-json-importerror-cannot-import-name-json-fr and another one on GitHub that tells me to essentially change the MarkUpSafe and itsdangerous installation again https://github.com/aws/aws-sam-cli/issues/3661, I have also tried to make a virtual environment named
veganetworkscriptenv to install the packages but that has also failed as well. I am currently using Flask 2.0.0 and Docker 5.0.0 and the error occurs on line eight in vegamain.py.
Here is the full ImportError that I get when I try and run the program:
veganetworkscript-backend-1 | Traceback (most recent call last): veganetworkscript-backend-1 | File "/app/vegamain.py", line 8, in <module> veganetworkscript-backend-1 | from flask import Flask veganetworkscript-backend-1 | File "/usr/local/lib/python3.9/site-packages/flask/__init__.py", line 19, in <module> veganetworkscript-backend-1 | from . import json veganetworkscript-backend-1 | File "/usr/local/lib/python3.9/site-packages/flask/json/__init__.py", line 15, in <module> veganetworkscript-backend-1 | from itsdangerous import json as _json veganetworkscript-backend-1 | ImportError: cannot import name 'json' from 'itsdangerous' (/usr/local/lib/python3.9/site-packages/itsdangerous/__init__.py) veganetworkscript-backend-1 exited with code 1
Here are my requirements.txt, vegamain.py, Dockerfile, and docker-compose.yml files:
Flask==2.0.0 Flask-SQLAlchemy==2.4.4 SQLAlchemy==1.3.20 Flask-Migrate==2.5.3 Flask-Script==2.0.6 Flask-Cors==3.0.9 requests==2.25.0 mysqlclient==2.0.1 pika==1.1.0 wolframalpha==4.3.0
# Veganetwork (C) TetraSystemSolutions 2022 # all rights are reserved. # # Author: Trevor R. Blanchard Feb-19-2022-Jul-30-2022 # # get our imports in order first from flask import Flask # <-- error occurs here!!! # start the application through flask. app = Flask(__name__) # if set to true will return only a "Hello World" string. Debug = True # start a route to the index part of the app in flask. @app.route('/') def index(): if (Debug == True): return 'Hello World!' else: pass # start the flask app here ---> if __name__ == '__main__': app.run(debug=True, host='0.0.0.0')
FROM python:3.9 ENV PYTHONUNBUFFERED 1 WORKDIR /app COPY requirements.txt /app/requirements.txt RUN pip install -r requirements.txt COPY . /app
version: '3.8' services: backend: build: context: . dockerfile: Dockerfile command: 'python vegamain.py' ports: - 8004:5000 volumes: - .:/app depends_on: - db # queue: # build: # context: . # dockerfile: Dockerfile # command: 'python -u consumer.py' # depends_on: # - db db: image: mysql:5.7.22 restart: always environment: MYSQL_DATABASE: admin MYSQL_USER: root MYSQL_PASSWORD: root MYSQL_ROOT_PASSWORD: root volumes: - .dbdata:/var/lib/mysql ports: - 33069:3306
How exactly can I fix this code? thank you!
The import failure seems to be related with the latest release version of the package
Check the latest releases here
In my case, I made it work by explicitly adding the package dependency
itsdangerous==2.0.1 in my
To make changes effective, update your virtual environment to reflect the new
The root of this issue appears to be that Flask 2.0.0 is unsupported. Try using the latest version of Flask.
As of March 8 2022, the latest version is 2.0.3:
pip install Flask=2.0.3
See Flask source code on Github for the most current version.
itsdangerous==2.0.1 to my
requirements.txt file, and downgrading to
Flask==1.1.1 fixed it for me.
Solution 1 - Upgrade the Flask to latest version i.e, 2.0.1 or above. It's the recommended way to fix the issue.
pip install Flask=2.0.1
pip install Flask=2.1.0
Solution 2 - Since it difficult to upgrade to latest version of Flask in shorter time, you can try below methods to resolve the issue.
you can continue using the Flask version 1.1.2 and try downgrading the itdangerous to 2.0.1. You can do this by adding
itsdangerous==2.0.1 to your requirements.txt file.
Solution 3 - Another way is to upgrade Flask from 1.1.2 to 1.1.4 as it does not have ground breaking changes and also downgrade the markupsafe library to 2.0.1
Once you upgrade from Flask 1.1.2 to 1.1.4 you will face another issue after, which is ImportError: cannot import name ‘soft_unicode’ from ‘markupsafe’ in Release 1.38.0 #3661, and that can be fixed by downgrading the markupsafe to version 2.0.1 as shown below.
pip install Flask==1.1.4 pip install markupsafe==2.0.1
I just put
itsdangerous==2.0.1 in my requirements.txt .Then updated my virtualenv using
pip install -r requirements.txt and then
docker-compose up --build . Now everything fine for me. Didnot upgrade the flask version.