TextInput class 
Is there any way to append or edit text ???
Problem:
I created TextInput object and accessed text method to print strings.
But every time I access text method, it prints new string and it doesn't retain previous value.
How to fix the issue?
what is alternative for TextInput?
Just replace the text with some function of the original string, e.g. textinput.text = ''.join('something ', textinput.text.replace('a', 'b'), ' and something else').
edit or append text (TextInput class) in kivy