Logging for Flask does not print to .log file even with debug=True-CodePudding

I'm trying to get my Flask app to print its logs onto a file named "backend.log". I tested it on a dummy Flask app, with the following script:

import logging
from flask import Flask

app = Flask(__name__)
logging.basicConfig(filename="backend.log", level=logging.DEBUG, format="%(asctime)s:%(levelname)s:%(message)s")

@app.route("/")
def home():
    return "<h1>Hello World!</h1>"

if __name__ == "__main__":
    app.run(debug=True)

This worked fine, and printed the following onto "backend.log".

2022-08-17 02:01:59,793:INFO: * Running on http://127.0.0.1:5000 (Press CTRL C to quit)
2022-08-17 02:01:59,796:INFO: * Restarting with stat
2022-08-17 02:02:00,114:WARNING: * Debugger is active!
2022-08-17 02:02:00,123:INFO: * Debugger PIN: 117-718-608

However, when I tried on a different repo/folder with my actual Flask app that I'm working on, it doesn't work anymore. The logging keeps printing to the console.

import logging
from flask import Flask
from endpoints.database_endpoints import database 
from endpoints.model_endpoints import model
from endpoints.workspace_endpoints import workspace


# Flask setup
app = Flask(__name__)
app.register_blueprint(database, url_prefix="")
app.register_blueprint(model, url_prefix="")
app.register_blueprint(workspace, url_prefix="")

# Logging setup
logging.basicConfig(filename="backend.log", level=logging.DEBUG, format="%(asctime)s:%(levelname)s:%(message)s")

@app.route("/")
def home():
    return "<h1>Endpoint is up and running</h1>"


if __name__ == "__main__":
    app.run(debug=True)

Console result:

 * Serving Flask app 'index' (lazy loading)
 * Environment: development
 * Debug mode: on
2022-08-17 02:08:30,111:INFO -  * Running on http://127.0.0.1:5000 (Press CTRL C to quit)
2022-08-17 02:08:30,113:INFO -  * Restarting with stat
2022-08-17 02:08:30,708:WARNING -  * Debugger is active!
2022-08-17 02:08:30,716:INFO -  * Debugger PIN: 117-718-608

There also wasn't a "backend.log" file created, either, unlike before. What am I missing here?

CodePudding user response：

Ok so I tested a couple of things, and apparently it was because the blueprint imports messed with the logging. See this post: How do I log a Python error with debug information?

Solution:

# Logging setup must be done before imports
import logging
logging.basicConfig(filename="backend.log", level=logging.DEBUG, format="%(asctime)s:%(levelname)s:%(message)s")

from flask import Flask
from endpoints.database_endpoints import database 
from endpoints.model_endpoints import model
from endpoints.workspace_endpoints import workspace

# Flask setup
app = Flask(__name__)
app.register_blueprint(database, url_prefix="")
app.register_blueprint(model, url_prefix="")
app.register_blueprint(workspace, url_prefix="")

@app.route("/")
def home():
    return "<h1>Endpoint is up and running</h1>"


if __name__ == "__main__":
    app.run(debug=True)