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ImportError: No module named sqlalchemy

由 若如初见. 提交于 2019-12-02 16:58:54

Did you install flaskext.sqlalchemy? It looks like you have the SQLAlchemy package installed but not the flask Extension. Try pip install Flask-SQLAlchemy or easy_install Flask-SQLAlchemy. It is available in the cheeseshop so either utility should pick it up.

sibande

I just experienced the same problem. Apparently, there is a new distribution method, the extension code is no longer stored under flaskext.

Source: Flask CHANGELOG This worked for me:

from flask_sqlalchemy import SQLAlchemy
Ming Liu

This works for me:

sudo pip install flask_sqlalchemy
sudo pip install sqlalchemy

Then in your code use:

from flask_sqlalchemy import SQLAlchemy
webminal.org

Okay,I have re-installed the package via pip even that didn't help. And then I rsync'ed the entire /usr/lib/python-2.7 directory from other working machine with similar configuration to the current machine.It started working. I don't have any idea ,what was wrong with my setup. I see some difference "print sys.path" output earlier and now. but now my issue is resolved by this work around.

EDIT:Found the real solution for my setup. upgrading "sqlalchemy only doesn't solve the issue" I also need to upgrade flask-sqlalchemy that resolved the issue.

try this:

from flask.ext.sqlalchemy import SQLAlchemy

This code works perfectly:

import sqlalchemy

Maybe you installed the package in another version of the interpreter?

Also, like Shawley pointed out, you need to have the flask extension installed in order for it to be accessible.

So here is an idea!

Since it seemed to work somewhere else.

install python-virtualenv and optionally you can install virtualenv-wrapper (which is pretty cool to create projects and so on)

In each env, you might have different versions of eggs. In other word, you could have sqlalchemy 1 and sqlaclhemy 1.5 in two different envs and they won't conflict with each others. It seems that you have a problem with your currently installed eggs.

So here we go:

virtualenv --no-site-packages foo
source foo/bin/activate

The parameter --no-site-packages will create a virtualenv and not use the packages already installed on your computer. It's pretty much like a bare python install.

source foo/bin/activate loads the virtualenv.

It's not that really userfriendly. And that's why http://www.doughellmann.com/projects/virtualenvwrapper/ exists.

That said, you should see somthing like thant in your terminal "(foo)user@domain$:" once your virtualenv is activated. It means that you can go on!

Then you have to do.

python setup.py develop of your project. It should download and install dependencies of your project in the virtualenv located in foo. If you need to install anything else, please use pip or easy_install without using sudo. When using virtualenv, you almost never need to use sudo. Sudo will install package in your global python install while it's not required and not really desirable.

If something happens in your virtualenv, you can always delete it and create a new one. This is no big deal. No need to mess with anything. Doesn't work? start over, do pip install -U if needed, define the versions if needed and so on.

Last but not least, in the other answers, it seems that the import changed. If the new versions for flask-sqlalchemy is located somewhere else, you should update your import or install the version you used to use.

first install the library

pip install flask_sqlalchemy

after that 

from flask_sqlalchemy import SQLAlchemy

put this in app.py file to get the access of database through SQLAlchemy

George Mogilevsky

Solution for me was to use:

from flask_sqlalchemy import SQLAlchemy

instead of 

from flask.ext.sqlalchemy import SQLAlchemy
RiceCrispy

Very late to the party but hopefully this will help someone, was in the same situation for about a hour without any of the solutions mentioned above working. (On a Windows 10 machine).

In the Settings/Preferences dialog (Ctrl+Alt+S), from the side menu select Project: | Project Interpreter.

Check which packages you currently have installed (You need SQLAlchemy and Flask-SQLAlchemy). Double click on any package name, an 'Available Packages' menu will open.

Search for the missing package(s) and click install.

On Windows 10 @ 2019

I faced the same problem. Turns out I forgot to install the following package:

pip install flask_sqlalchemy

After installing the package, everything worked perfectly. Hope, it helped some other noob like me.

标签
python
sqlalchemy
flask-sqlalchemy
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