Flask - ImportError: No module named app

问题:

First I created __init__.py

from flask import Flask

app = Flask(__name__)

Then in a separate file, in the same directory, run.py

from app import app 

app.run(
    debug = True
)

When I try to run run.py, I get the error

Traceback (most recent call last):
  File "run.py", line 1, in <module>
    from app import app 
ImportError: No module named app

回答1:

__init__.py is imported using a directory. if you want to import it as app you should put __init__.py file in directory named app

a better option is just to rename __init__.py to app.py

回答2:

Your __init__.py file needs to go in the folder named app, not the same directory as the run.py file.

from app import app is looking in the app folder, so the __init__.py file needs to sit in there.

回答3:

This is probably an error in flask application's folder structure.
Anyone looking for a simple beginner-friendly structure for the flask project may find this helpful:

   |__movies 
     |__run.py 
     |__app     
        ├── templates
        │   └── index.html
        │   └── signup.html
        └── __init__.py
        └── routes.py

Here 'movies' is the name given for the main application. It contains 'run.py' and a folder called 'app'. 'app' folder contains all necessary flask files such as 'templates' folder, '__init __.py', and 'routes.py'.

Contents of:

run.py:

from app import app

__init.py__:

from flask import Flask

app = Flask(__name__)

from app import routes


app.run(debug=True)

routes.py:

from app import app

@app.route('/')
@app.route('/index')
def index():
    return "Hello, World!"