How to print from Flask app route to python console

Question

I would like to simply print a  hello world  to the python console after  button is called by the user   This is my naive approach    app route   button    def button clicked        print  Hello world       return redirect        Background  I would like to execute other python commands from flask  not shell    print  should be the easiest case  I believe I have not understood a basic twist here  Thanks in advance

User · Answer

We can also use logging to print data on the console.

Example:

import logging
from flask import Flask

app = Flask(__name__)

@app.route('/print')
def printMsg():
    app.logger.warning('testing warning log')
    app.logger.error('testing error log')
    app.logger.info('testing info log')
    return "Check your console"

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

User · Answer

I tried running  Viraj Wadate s code  but couldn t get the output from app logger info on the console  To get INFO  WARNING  and ERROR messages in the console  the dictConfig object can be used to create logging configuration for all logs  source   from logging config import dictConfig from flask import Flask   dictConfig        version   1       formatters     default              format       asctime s    levelname s in   module s    message s                handlers     wsgi              class    logging StreamHandler            stream    ext   flask logging wsgi errors stream            formatter    default               root              level    INFO            handlers     wsgi              app   Flask   name      app route      def index        return  quot Hello from Flask s test environment quot    app route   print   def printMsg        app logger warning  testing warning log       app logger error  testing error log       app logger info  testing info log       return  quot Check your console quot   if   name         main         app run debug True

User · Answer

It seems like you have it worked out  but for others looking for this answer  an easy way to do this is by printing to stderr  You can do that like this   from   future   import print function   In python 2 7 import sys   app route   button    def button clicked        print  Hello world    file sys stderr      return redirect        Flask will display things printed to stderr in the console  For other ways of printing to stderr  see this stackoverflow post

User · Answer

I think the core issue with Flask is that stdout gets buffered  I was able to print with print  Hi   flush True   You can also disable buffering by setting the PYTHONUNBUFFERED environment variable  to any non-empty string

[python] How to print from Flask @app.route to python console

Examples related to python

Examples related to flask