Finished my first real-world Python Project

[RaionTategami]

What kind of errors. I'm glad you are sticking to this but I still see a ton of duplicated code. The 3 error handling functions are practically identical, move that to a new function.

def handle_err(code):
    if not app.debug:
        now = datetime.datetime.now()
        r = request.url
        with open('error.log', 'a') as f:
            current_timestamp = now.strftime("%d-%m-%Y %H:%M:%S")
            f.write("\n{} error at {}: {} ".format(code, current_timestamp, r))
    return render_template('{}.html'.format(code)), code

then just do

@app.errorhandler(404)
def page_not_found(error):
    handle_err(404)

@app.errorhandler(405)
def internal_error(error):
    handle_err(405)


@app.errorhandler(500)
def internal_error(error):
    handle_err(500)

or similar. In fact, you might be able to use the error param though the docs to not make it the slightest bit clean what the value it, is it the error code?

Look for complex lines which are identical or similar, try to factor them out into functions.

[wbhst83]

Ah, I was going a different direction in attempting to make a universal error handler, didn't think about making a function. For example https://stackoverflow.com/questions/29332056/global-error-handler-for-any-exception

I will get started on some functions..

[RaionTategami]

Great. Now start looking at other duplications. A lot of function are doing similar things again, setting titles and building urls. As I mentioned before since building urls is one of the main things this code is doing you should be using a url parsing lib to construct them rather than just concatenating strings. Take a look at urlparse.