old_contents: from flask import Flask, render_template
  from traffic import *
  
  app = Flask(__name__)
  
  
  @app.route("/")
  def root():
      err_msg = "Please check vnstat version >= 1.14"
      try:
          data = load_json_data()
      except subprocess.CalledProcessError:
          print(err_msg)
          return err_msg
      df = create_df(data)
      daily, curr = traffic_in_month(df)
      monthly = traffic_in_last_year(df)
      print(daily)
      print(monthly)
      return render_template('traffic.html', daily=daily, monthly=monthly)
  
  
  if __name__ == "__main__":
      app.run()
  
new_contents: from flask import Flask, render_template
  from traffic import *
  
  app = Flask(__name__)
  
  
  @app.route("/")
  def root():
      err_msg = "Please check vnstat version >= 1.14"
      try:
          data = load_json_data()
      except subprocess.CalledProcessError:
          print(err_msg)
          return err_msg
      df = create_df(data)
      daily, curr = traffic_in_month(df)
      monthly = traffic_in_last_year(df)
      return render_template('traffic.html', daily=daily, monthly=monthly)
  
  
  if __name__ == "__main__":
      app.run()
  
subject: Remove print