turtle.circle(radius, extent=None, steps=None)
Parameters:
radius – a number
extent – a number (or None)
steps – an integer (or None)
Draw a circle with given radius. The center is radius units left of the turtle; extent – an angle – determines which part of the circle is drawn. If extent is not given, draw the entire circle. If extent is not a full circle, one endpoint of the arc is the current pen position. Draw the arc in counterclockwise direction if radius is positive, otherwise