title: API tkinter python entry
body: <p>I have a problem with the entry. I want the user to write in any city they want in the<br>
  API link. I get that i cant convert to a str. So when ever the user choose to enter a city he can just click on the button forecast after he entered the city in the Entry and the weather will be printed:</p>
  
  <pre><code>from tkinter import *
  import requests
  import json
  
  class Application(Frame):
  
      def __init__(self, master=None):
          Frame.__init__(self, master)
          self.root = master
          self.pack()
          self.create_widgets()
  
      def create_widgets(self):
          self.v = StringVar()
          self.e = Entry(self, textvariable=self.v)
          self.e.pack(side="left")
  
          self.v.set("Enter City")
          self.s = self.v.get()
          self.e.focus_set()
  
  
          self.butn = Button(self)
          self.butn["text"] = "Forecast"
          self.butn["command"] = self.make_request
          self.butn.pack(side="left")
  
          self.QUIT = Button(self, text="QUIT", command=self.root.destroy)
          self.QUIT.pack(side="right")
  
  
      def make_request(self):
          r = requests.get("http://api.wunderground.com/api/ab78bcbaca641959/forecast/q/Sweden/" + ???? + ".json")
          data = r.json()
          for day in data['forecast']['simpleforecast']['forecastday']:
              print (day['date']['weekday'] + ":")
              print ("Conditions: ", day['conditions'])
              print ("High: ", day['high']['celsius'] + "C", "Low: ", day['low']['celsius'] + "C", '\n')
          return data
  
  
  
  
  
  
  rot = Tk()
  rot.geometry("900x650+200+50")
  rot.title("The Trip")
  
  app = Application(master=rot)
  app.mainloop()
  </code></pre>