Question

I stumbled upon this article and followed all steps. But pyDev won‘t see my flask extensions and that‘s really annoying. There‘s only one thing (and I think this is the key):

Touch /site-packages/flaskext/__init__.py

Touch is a unix util I think. Is there an equivalent to this on Windows?

Answer 1

The Eclipse uses static analysis of modules by default. flask.ext builds import list dynamically. To force dynamic analysis using Python shell add flask.ext to forced builtins list.

Go to Preferences -> PyDev -> Interpreters -> Python Interpreter. Select your interpreter, go to Forced Builtins tab. Click New... and enter flask.ext.

This requires PyDev to forcefully analyze module through a shell.

For more details see PyDev manual.

Answer 2

I‘m also struggling with this and the problem seems to be in the way that Flask imports the extensions. If you open the flask/ext/__init__.py file you‘ll see it uses importer. I don‘t think PyDev likes this much, so I‘ve edited this file with the fixed imports:

import flask_login as login
import flask_sqlalchemy as sqlalchemy
import flask_wtf as wtf

def setup():
    from ..exthook import ExtensionImporter
    importer = ExtensionImporter([‘flask_%s‘, ‘flaskext.%s‘], __name__)
    importer.install()


setup()
del setup

I‘ve also found that Flask-SQLAlchemy imports broke too, so instead of doing db.Column as explained in the documentation, directly use sqlalchemy import, i.e. from sqlalchemy import Column, ForeignKey

Answer 3

If you have your project in a virtual environment and you want add the project in eclipse so that the project uses libraries that are installed on the virtual environment, then you should follow the following steps.

step 1: let‘s say the absolute path to your virtual environment is: C:\Users\sadegh\Desktop\flask_eclipse\fe\venv

go to window->preferences->PyDev->interpretors->Python Interpretor in the Scripts directory, there is python.exe  which is the python interpreter that has been assigned to this virtual environment. This executable will be the new python interpreter that we will add to eclipse.

step2: Go to window->preferences->PyDev->Interpreters->Python Interpreter 

In the right pane you will see this: 

click on new button then this window will pop up: 

write anything you want in the Interpreter Name field and write the absolute path of the python.exe file that was mentioned in step 1 in the Interpreter Executablefield

after clicking OK this will pop up: 

select all the items then click OK

step3: select the newly added interpreter in the above pane, then in the below pane go to Forced Builtin tab and click on new button on right hand side of this below pane.

and in the window that pops up write flask.ext.

step4: everything is set now:

if you want to start a new project: when you are creating a new PyDev Project select the new Interpreter that we created as the Interpreter of this project. 

if you want to convert an existing project to a flask project on your virtual environment right click on project and go to properties and in PyDev-Interpreter/Grammar change the Interpreter to the new interpreter that we have created.

note: If you want the eclipse to run the server for you in the virtual environment you can run the server from within the code that contains the Flask() instance like this:

if __name__ == ‘__main__‘: #here i assume you have put this code in a file that    
   app.run()   #contains variable "app", which contains the instance of #Flask(__main__)

Answer 4

touch will create a blank file if it doesn‘t exist, or update the file‘s modification time if it does exist.

For this purpose, echo > /site-packages/flashext/__init__.py at a command-line should suffice. (The file won‘t be blank, but only contains a single newline which is semantically equivalent for Python).