Unit 3: Programming with Python

python prompt

>>>is a symbol that begins the program, standing 'ready to receive' your instructions. This prompt basically says "ready"

Compiler

A program that translates code in a high-level language (such as Python) and converts it into binary machine language.

Code

A way of conveying information as symbols. Symbols that have meaning when read in a predefined way

interactive mode

A way of using the Python interpreter by typing commands and expressions at the prompt.

Natural Language

Any one of the languages that people speak that evolved naturally. Ambiguous; many different meanings for the same word

Program's 3 parts

Input - entering data into the computer processing - data being manipulated to do what is intended output - a provided result in some format

Assembly Language

It abstracts the information provided by a high level language (Python for example) into a middle level language which will then convert it to machine language

unary operator

an operator that has only one operand and applies only to the one number after it; example => -3 (negation modulus)

binary operator

an operator that has two operands and refers to them both (2 + 2)

object-oriented programming

designing a program by discovering objects, their properties, and their relationships

sequential

doing steps after one after the other in the order they are listed. for example, not trying to call a function before creating a function

reassigning variables

make it equal to the new value example: teacher = Mr. Morton teacher = Ms Del-Sette

semantics

meaning of statement, what happens when the statement is executed. It's exact. English isn't. "That's cool" can mean different things.

key words

reserved words that have a special meaning in python and can not be used as variables example: if, while, for, class

% modulus

returns the remainder only ie 17 % 3 = 2 (15, r 2)

Syntax

the structure, rules, and correct format for writing a programming language

data types

three main data types in Python; strings integers and floats, booleans, dictionaries, sequences, sets

graphic shapes

variable = Circle(radius) variable.set_position(x, y) variable.set_color(color.black) add(variable)

graphics text

variable = Text("fill") variable.set_position(x, y) - refers to bottom left variable.set_color(color.black) variable.set_font("50pt Arial") add(variable)

Python Rectangles

variableName = Rectangle(width, height) variable.set_color(color.red) variable.set_position(x, y) - refers to top left corner add(variable)

input function when an integer is required

when you are requiring the user to enter a whole number it requires "int" added to the input statement. example: number = int(input("Enter a number: "))

Python Canvas

* Coordinate System * Top Left (0, 0), Bottom Right (400, 400) get_width() - get canvas width get_height() - get canvas height

Programs are developed to:

* Express Creativity * Satisfy personal curiosity * Create new knowledge * Satisfy a common need (Netflix)

parts of a variable

1. the name, 2. its data type - int, float, str, 3. its value

Data type determines

1. the possible values for that variable 2. operation that can be done with the value 3. meaning of the data 4. the way value of that type get stored

Python Facts

1.Created in late 1980's by Guido Van Rossum 2.named from Monty Python's Flying Circus Tv Show 3. It is open-sourced 4. One of the official languages of Google and Mozilla Firefox

Order of Operations

PEMDAS

script mode

allows us to store python script source code in a file with the .py extension and then use the interpreter to execute the contents of the source file

Programming language

Provides the standards, syntax, statements, and instructions for writing a language that our computer can understand. Not ambiguous - has one meaning

Open Source

Software that is created for free use by everyone

Machine Language

The language made up of binary-coded instructions that is used directly by the computer. Low level language

variable (Identifiers)

What we work with in python, its a name we assign a value to

assignment statement

allows us to assign and update a value to a variable. Has a name, an equal sign, and a value.

Pseudocode

Writing out in natural language what you want your code to do

prototype

a drawing of what your code should look like

Callback function

a function that is triggered by another function in response to some event. We bind a function to the mouse click event then pass the information to that function. Ie) def click(x, y) #action to take place #when mouse clicked add_mouse_click_handler(click)

input function

a function that prints a prompt asking for text from the user example: name = input("What is your name: " ) print (name)

Algorithm

a step-by-step procedure for solving a problem, a combination of algorithms make up a program

mouse click events

allow user interaction in our program