Introduction to

Python

by:

Behnam Khan Beigi (yottanami)

Sameer Rahmani (lxsameer)

from:

Who we are ?

Karaj LUG

What is LUG ?
What do you do in LUG ?
What did you do in FOSS world ?
Karajlug community
How can I join karajlug
I'm not a linux expert , can I still join Karajlug ?

Learn more about Karajlug in:

We . . .

have about 12 years experience in GNU/Linux
have 8 years experience as senior developer in Yellowen
have 3 years experience in Yellowen SRE team
have over thousands of contributes to FOSS world
are official GNU project developer

Expert in:

PHP, Python, Ruby, Javascript, C/C++,Perl, Lua

Many successful projects

Why Python ?

Python is fast
Python is broad
Readablity
Python is easy to learn
It`s open
It's dynamic
Python is a general purpose language
It's cross platform
And much more reasons

Python is fast

Python is faster than other

"scripting" languages.

Python implemented specific parts

of language in C

Python has other implementations that

provide some solutions to increase

runtime speed dramatically.

PyPy

PyPy is an implementation of python written in python
PyPy implemented a JIT
It's about 5time faster that Cython ( yeah Cython )

Numba

It`s a JIT to use you python code

It's very easy to use (just a decorator)

It can be use with legacy code too

Python is broad

Python can be used in many different

fields like:

Web development
System administration
Game development
3D modeling
Testing
Analyzing big data
. . .

Readability

Just take a look

from some_package import some_method

def say_hello (name=none):
    if name is not none:
        print("Hello " + name)
    else:
        print("Hello world")

say_hello("yottanami")

It's easy to learn

Its syntax is very simple and English like
Python does not use wired symbols or structures
Lots of resources out there
Python is very popular

Free Software

Python is open source and free (libre)

It means that you can

get the source code

change it as you need

and redistribute it

People can find bugs and fix them faster

Python is dynamic

What is a dynamic language ?

new code can be executed during runtime

without limitations

What's the point ?

It means that the user does not have to go through

the compile-run-debug cycle every time he makes

a change to the code

Python is general purpose

You can use python in

Desktop apps
Hand held applications
Embedded Systems
Electronics
Robotics
Game development
Manufacture
etc

Cross Platform

This OS`s supports python:

GNU/Linux
BSD family
MS Windows
Android (It's Linux ofcourse)
Mac
iOS
Solaris
.....

Who use python?

NASA
Google
Youtube
Source Forge
Disqus
Karajlug :P
Pintrest
Instagram
Mozilla
BitBucket

Get start

Installation

Windows

GNU/Linux

Android

Editors & IDEs

Eclipse + pydev
Eric5
Geany
Wing IDE
Vistual Studio
Sublime text
Emacs
Kuso
Atom
Notepad++
VIM

What do we need today?

Python ( of course)
pip
IPython
An editor or IDE

How to use Python

How to run python scripts
How to use Python shell
How python runs scripts
How to install packages using pip
Some useful packages

How to run a python script ?

If target script contains hashbang section:

$ python /path/to/target_script.py
$ chmod +x /path/to/target_script.py # another way
$ /path/to/target_script.py

If target script does not have hashbang section:
```
$ python /path/to/target_script.py 
```

Useful pakcages

Ipython
bpython
virtualenv
pep8
winpdb

A simple trick

Learn faster by:

`help` function
`dir` function
`__dict__` method

Basics

Variables
General types
Indentation & Code blocks
Operators
Conditions
Loops
Functions
Exceptions
Modules
OOP

Variables

What is a variable
How we define a variable
Variable scopes

Data Structures

String
Numbers
Lists
Tuples
Dictionaries

Strings

Strings define using single or double quote
Strings are immutable
characters of an string are accessible using
[] operatore

Numbers

Numbers are objects too

There are different types of numbers

Float, Integer, Long and etc

Lists

Lists are mutable
Think of lists as array in other langs but more flexible
List can have elements with different types
List elements are accessible by [] operator

Tuples

Tuples are just like lists but immutable

Dictionaries

Dictionaries are mutable
Dictionaries are lists with flexible indexes
Index of dictionaries can be an object
Dictionary values are accessible using [] operator

Indentation

What does it means ?
What is a code block ?
How we defines code blocks ?

Operators

Math operators ( +, -, *, /, **)
Logical operators ( <, >, <>, == , <=, >=, and, or, not)
Assignment operators (*=, +=, -=, /=)
Binary operators (<<, >>, &, |, ^)
Membership operators (in, not in)

Conditions & Loops

if - if/else
for
while
iterators

Functions

What is a function
What is a method
How to define a function
Function arguments
Return values

Exceptions

What is an exception?
When does exceptions raises?
How to catch exceptions

OOP

What is OOP ?
How does it help us?
How can i define a class ?
How can i define attributes ?
How can i define methods ?
What is inheritance ?

Where to get help ?

Python documents
Search the web
Python forums
IRC channels
Mailing Lists
LUGs & PUGs

Resources

Python for data analysis ISBN 1449319793
Data Structures and Algorithms in Python
ISBN 1435455002
Python For Dummies ISBN 0471778648
Python Programming for the Absolute Beginne
ISBN 1435455002
Byte of python
Dive into python

Do you have any question ?

Web:
Karajlug.org
IRC :
irc.freenode.net #5hit channel
ML :
https://lists.nongnu.org/mailman/listinfo/karajlug-general
twitter :
@yottanami @lxsameer
Email:
yottanami@gnu.org
lxsameer@gnu.org


try:
    run_a_workshop()
    print("Good job guys")
except PeopleDidNotLearn:
    print("We have to try harder")
finally:
    print("Heeeell yeah, It's finished")