Learning Python: CS 1

binary number system

first generation language (1GL), the same thing as the machine’s native language (machine language) where numbers represent the commands and data for the program

machine language are the binary numbers representing instructions that the computer interprets

machine language (binary) -> hexadecimal language

made it a bit easier to enter programs

assembly language

second generation language (2GL)

came later and made it even easier

each command uses a mnemonic and a program called a compiler changes the mnemonics into numbers that represent the commands

(but it’s still not very easy to program)

the next generation of languages allowed for higher-level abstractions

COBOL, FORTRAN, LISP

a compiler takes the program typed in by the user (source code) and turns it into machine code

a program compiled for windows does not work on a mac and so on

but a program can be run using an interpreter program that look at the source code and interpret it to machine language instructions on the fly

they are a bit slower but easier programming languages

python is an interpreted language; it must have a python interpreter to work and runs slower than c, but it’s easier to develop in python than c

there are specialised languages for different task: 

c for operating systems

php for web pages

python for general purposes, easy to use

almost all languages share the same common elements, and once one language has been learned, the same theories will apply to the other languages

if you want to repeat a certain number of times, use a for loop. if you want to repeat until something happens (like the user clicks a button), use a while loop.

random numbers generated by python:

import random

randrange(min, max) generates an integer

random() generates a floating point number between 0 and 1