title: Return text from radio buttons
body: <p>I'm trying to create a search bar in kivy with only pure python. Is there any way to return a certain string to a function from selecting a radio button </p>
  
  <p>This is a small snippet from my program. It would be helpful if you could answer using pure python codes </p>
  
  <pre><code>class avbl_bk(Screen):
      def __init__(self,**kwargs):
          super(avbl_bk,self).__init__(**kwargs)
          blayout=BoxLayout(orientation="vertical")
          check=BoxLayout()
          search_layout=BoxLayout(spacing=10,padding=5)
          search_label=Label(text="Search: ",size_hint_x=0.5)
          search_box=TextInput(multiline=False,font_size=40,size_hint_x=0.8)
          search=Button(text="Search",size_hint=(.3,0.8))
          chk1=CheckBox(group='1')
          chk2=CheckBox(group='1')
          chk3=CheckBox(group='1')
          chk4=CheckBox(group='1')
          chk5=CheckBox(group='1')
          chk6=CheckBox(group='1')
          filters=["ISBN","Book","Genre","Author","Publisher","Copies"]
          for i in range(6):
              check.add_widget(Label(text=filters[i]))
              check.add_widget(eval(("chk"+str(i+1))))
          search_layout.add_widget(search_label)
          search_layout.add_widget(search_box)
          search_layout.add_widget(check)
          search_layout.add_widget(search)
          blayout.add_widget(search_layout)
          self.add_widget(blayout)
  </code></pre>