Working with files in Python is pretty easy. But there’s a common mistake that can sneak into your code. Not closing the file ...

IPython Console - this is a powerful interactive Python shell. For example, it makes system commands available directly and it allows you to see plots inline. There are many good features of IPython.

Without functions: by repeatedly writing the code to draw a triangle with. With a Python function call: by generating lots of coordinates and feeding them to your “draw triangle” function.