flask_blog | Python Flask开发的博客系统 - 修改 app create_app

It looks like your source files are messed up. Try to reinstall the dns library. If it does not help, manually edit the file C:\Users\Aadish\AppData\Local\Programs\Python\Python39\lib\site-packages\dns\name.py to fix the problem.

You should change the class notation as follows. This goes for all fields where you want to add classes. See documentation at https://wtforms.readthedocs.io/en/2.3.x/fields/

Your snippets don't show where Initial_checks comes from.

Looks like it is trying to use connection as a context manager.

In the first case it works because it is passed the return value of psycopg2.connect.

In the second case (init_app) it doesn't work because

• you're passing it a PostgresConnection instance, not the connection attribute
• the connection attribute is not set at import time anyway

The problem lies in the fact that you're calling Initial_checks at import time while your connection can only be ready at app init time.

Those checks should be postponed to init time.

There is a typo in your code. You should use db.Column with uppercase C instead of db.column. So, your code should be like that:

If you will look at you error closely from urabncloth import app

Looking at your directory there is no urabncloth it is urbancloth. Just a typo.
So in your routes.py change the package name.

Hope this solves your problem!!!

You may need to update your notebook_file and notebook_type to be of type db.Text, unless you really need the constraint (in which case you can add a CHECK constraint to your database. Also, varchar(N) is often not recommended (there are many other similar blog articles). Also, in SQLite, varchar(N) is not really enforced, which may explain why you were able to get away with no errors previously.

Otherwise, please update your original post with proof that you are getting the error message while not attempting to enter a notebook_file or notebook_type with greater than 20 chars.

Disclosure: I work for EnterpriseDB (EDB)

It looks like Flask is trying to run ./flaskblog.py directly for some reason, rather than with the python binary (python3 flaskblog.py), which is not working since flaskblog.py isn't executable.

So just add the following line (shebang) at the top of flaskblog.py

Issue raised in VsCode

Under Powershell, you have to set the FLASK_APP environment variable as follows:

$env:FLASK_APP = "webapp"

Then you should be able to run "python -m flask run" inside the hello_app folder. In other words, PowerShell manages environment variables differently, so the standard command-line "set FLASK_APP=webapp" won't work.

You need to set a proper DSN for SQLALCHEMY_DATABASE_URI environment variable. It needs to have a valid dialect prefix, like mysql, postgresql, or sqlite, as per docs:

https://docs.sqlalchemy.org/en/13/core/engines.html#database-urls