flask_simple_route.py

"""Remove redundancy and give function names meaning when using the route decorator.

@route
def home():
    return 'hello'

@route
def profile(username):
    return 'your name is ' + username

@route
def post(post_num: int):
    return '<h1>Post ID is %s </h1>' % post_num

Actual code with explanation below
"""

from flask import Flask

app = Flask(__name__)

def route(fn):
    fn_name = fn.__name__
    if fn_name == 'home':
        return app.route('/')(fn)
    annotations = fn.__annotations__
    if annotations:
        if len(annotations) == 1:
            key, value = list(annotations.items())[0]
            if isinstance(value, type):
                value = value.__name__
            else:
                raise RuntimeError('type annotation must be a type?')
            return app.route('/{}/<{}:{}>'.format(fn_name, value, key))(fn)
        else:
            raise RuntimeError('I do not know what I am doing.')
    else:
        code_obj = fn.__code__
        if code_obj.co_argcount == 1:
            return app.route('/{}/<{}>'.format(fn_name, code_obj.co_varnames[0]))(fn)


@route
def home(): # home mapped to /
    return 'hello'

@route
def profile(username): # will be /profile/<username>
    return 'your name is ' + username

@route
def post(post_num: int): # will be /post/<int:post_num>
    return '<h1>Post ID is %s </h1>' % post_num

# above now same as below
'''
@app.route('/')
def home():
    return 'hello'

@app.route('/profile/<username>')
def profile(username):
    return 'your name is ' + username

@app.route('/post/<int:post_num>')
def post(post_num):
    return '<h1>Post ID is %s </h1>' % post_num
'''

if __name__ == '__main__':
    app.debug = True
    app.run('0.0.0.0', debug=True)