Python Guide

By Dipsy Wong

Overview

Python is a scripting language, need an interpreter but not compiler, so it exist in text format but not an executable file.

Syntax Characteristic

Python does not require semicolon to separate different statements. Scope is started with colon : and defined by 4 space or 1 tab. (We will discuss scope later) Beginners of python are easily mess these syntax characteristics.

Get started

When start learning a new programming language, the first program is always hello world

print(“hello world”) 

Simple.

Variables

A variable is like a box. It stores thing in it, with a tag outside to reach it. Like x = 1 it is a box with a tag x and storing 1 in it. Apart from numbers, variable can also store string. For example mystr="hello"

We can also print out value of variables

x = 1
print(x) 
mystr = "hello"
print(mystr)

result:

1
hello

Calculation

Python follows mathematical calculation. You can have calculations like x = 1+2+34(1+3). There is order of operation (Operators Precedence) in python