old_contents: from flask import Blueprint, g
  
  web = Blueprint('web', __name__, template_folder='templates',
                  static_folder='static',
                  static_url_path='/web/static',
                  url_prefix='/<lang_code>')
  
  
  @web.url_defaults
  def add_language_code(endpoint, values):
      values.setdefault('lang_code', g.lang_code)
  
  
  @web.url_value_preprocessor
  def pull_lang_code(point, values):
      g.lang_code = values.pop('lang_code')
      if not g.lang_code.strip():
          print("No code :(")
          g.lang_code = 'en'
  
  
  from . import views  # noqa
  
new_contents: from flask import Blueprint, g, session
  
  web = Blueprint('web', __name__, template_folder='templates',
                  static_folder='static',
                  static_url_path='/web/static',
                  url_prefix='/<lang_code>')
  
  
  @web.url_defaults
  def add_language_code(endpoint, values):
      values.setdefault('lang_code', g.lang_code)
  
  
  @web.url_value_preprocessor
  def pull_lang_code(point, values):
      g.lang_code = values.pop('lang_code')
      # Tie user session to a particular language,
      # so it can be retrived when we pop the request values
      session['lang_code'] = g.lang_code
  
  
  from . import views  # noqa
  
subject: Use sessions to Tie it a with language. Also helps us to retrieve session code later " "