Flask SqlAlchemy Debugger

sqldebugger.py

'''
Flask SqlAlchemy Debugger (Python 3)
------------------------------------

Shows the actual "sql query equivalent" of Flask-SQLAlchemy for debugging purposes
and gives you a rough estimation of where in your application query was issued.

Only runs when you enable "FLASK_ENV=development", since this will automatically set the
"FLASK_DEBUG=1" or explicitly set "FLASK_DEBUG=1". If you are in "FLASK_ENV=testing" (testing mode)
or "FLASK_ENV=production" and you want to make it work without enabling the debugging mode, 
set "SQLALCHEMY_RECORD_QUERIES=True" in your flask configuration.

How to use it?
--------------
You can add this function to your "routes.py" file, using the decorator "@app.after_request"
or using this variant "app.after_request(sql_debug)".

I got the inspiration from dhrrgn, but decided to create my own.
https://gist.github.com/dhrrgn/6022858
'''

from flask_sqlalchemy import get_debug_queries

@app.after_request
def sql_debug(response):
    queries = list(get_debug_queries())

    if len(queries):

        print('=' * 80)
        print('          FLASK SQLALCHEMY, DEBUG SQL QUERIES:')
        print('=' * 80)
        print()

        total_duration = 0.0
        for i, q in enumerate(queries):
            total_duration += q.duration
            print("  Query({}): {}".format(i+1, q.statement))
            if q.parameters:
                l = len(str(i+1))+11
                print('{}{}'.format(' '*l, q.parameters))
            print("  Context: {}".format(q.context))
            print("  Duration: {}".format(round(q.duration*1000,2)))
            print()

        print('=' * 80)
        print('  Total SQL Queries:', len(queries))
        print("  Total Query Duration: {} ms".format(
            round(total_duration*1000,2)))
        print('=' * 80)
        print()
       
    return response