In Python please!!!!!!

Write a calculator program in Python with the following characteristics:

It must be at least 50 lines of code excluding comments

It must have the following functions:+,-,*,/, SQRT

It must be all text, no high resolution graphics

It must automatically copy the result to the operating system clipboard

It must work as a functional calculator (calculations can be entered over and over)

Please submit the source code only (.py), no object code (I will compile on receipt)