bptest.py

from flask import Flask, Blueprint, g

### site blueprint
site = Blueprint('site', __name__)
@site.url_value_preprocessor
def get_site(endpoint, values):
    # grab all subdomains, as an example
    site = values.pop('site_subdomain')
    g.site = site

@site.route('/')
def index():
    return 'This site has the subdomain %s.' % g.site


### post blueprint
post = Blueprint('post', __name__)

@post.route('/')
def index():
    if 'site' in g:
        return 'This is a view in the post blueprint, subdomain %s' % g.site
    else:
        return 'This is a view in the post blueprint, with no subdomain (which shouldn\'t really happen)'
    
@post.route('/example')
def example():
    return 'This is an example post'

### flask app
app = Flask(__name__)
app.config['SERVER_NAME']='test.inet:5000'

app.register_blueprint(site, subdomain='<site_subdomain>')
app.register_blueprint(post, url_prefix='/post')

@app.route('/')
def index():
    return 'This is the main site with no subdomain'