1: Get Ready For The Python Difference

Summary

• Objects do carry an indication of type, but variables are untyped

• Integers in python have an unlimited number od digits

• Variables store references to objects, not values

• Strings are immutable and support slicing

• The list does the work of an array in other languages

• The dictionary is essentially an associative array

• The tuple is a lightweight immutable list

• Code indentation alters the meaning and matters

• Classes are objects

• Objects have attributes, some of which can be functions

• Inheritance works much like other languages, but class objects are directly involved in retrieving attributes

• Modules are how Python Code is packed into larger units

Objects

Everything is an object

• The program (module)

• variables (names are just pointers)

• functions

• classes

Basic Python

s = "Strings" # no declaration like "int" or "str"
x = 5

#Math
sum = 5 + 4
sub = 5 - 4
product = 5 * 4
quotient = 5 / 4
remainder = 5 % 4
count = count += 1

#functions

def add(x,y):  # def is a python command that tells the program to look at the object that "add" points to
# notice the ":" when a colon is used everything underneath is a part of that line, this is used in loops, functions, and conditionals
    return x + y
print(add(2,3)) # prints 5

# can be done with strings as well ex add("lumber", "jack") prints "lumberjack"

Objects in Code

class point:
    def __init__(self): # the initializer
        self.position=(0,0)
    def setpos(self,x,y): #setter
        self.position=(x,y)
    def display(self): #getter
        print(self.position)

Modules

Python scripts can be an object themselves. Scripts can be imported as modules to other python programs which can access the original scripts objects, or only specific objects

import modulename