Introduction to Computer Science

What is Computer Science? The study of processes that transform information Related Fields: Computer Engineering Information Technology

Programming Languages Machine Language Assembly Language High-Level Language Machine language is written using binary code. Computer's native language. Consists of a fixed set of simple instructions that manipulate memory and machine registers. Machine language is also called object code. Assembly language is machine language in human-readable form. Think of it as 'decoded' machine language. Same set of instructions. A program called an assembler performs the simple translation to machine language. High-level languages like Basic, C#, and Java contain powerful instructions called source code that typically translate to several machine instructions. A compiler program performs the translation to machine language.

Executing Programs CPU does not understand high-level programming languages Programs in high-level languages must be either Translated to machine language using a ______________ Interpreted "on the fly" using an ______________ What are the benefits / tradeoffs?

Python Invented by Guido van Rossum in 1990’s Popular Cross Platform Used for: Scripting and System Administration Scientific computing Web applications Powers many Google apps

Python Programs Stored in files with a ______ extension Executed using Python interpreter

Let’s Program! Meet the Turtle

A Complete Python Program # Make the turtle move import turtle size = 100 turtle.forward(size) turtle.right(90) turtle.forward(size * 10)

Python Programs Python programs consist of Comments Statements # A comment starts with a hash mark # Comments are notes for the programmer, and are ignored by the Python interpreter Statements import turtle turtle.forward(size)