Python presentation with examples available on github. Main concepts can be found by exploring the small and concise code samples available. It presents some of Python's capabilities and characteristics. The code samples (end of June 2014) are tested with latest Python 2.7 but should be easily convertable to Python 3.

1. Python
A practical perspective

2. Purpose
Show some Python characteristics
Identify scenarios where it can be used
Learn by examples

3. Foreword
Using a programming language doesn’t
mean knowing everything about it
Experiment but focus on the purpose, not
the language!

4. The Zen of Python (PEP* 20)
Beautiful is better than ugly.
Explicit is better than implicit.
Simple is better than complex.
Complex is better than complicated.
…
* Python Enhancement Proposal
http://legacy.python.org/dev/peps/pep-0020/

5. Multi paradigm language
Imperative
Object oriented
Functional

6. Indentation delimits blocks
Python C/C++/Java
if IsOk():
DoThatOne()
DoAnotherOne()
DoFinal()
if ( IsOk() )
{
DoThatOne();
DoAnotherOne();
}
DoFinal();

7. Modules
import module_name
…
module_name.module_function(...)
module_name.variable
Details: https://docs.python.org/2/tutorial/modules.html

8. Functions
def MySum(param1, param2):
result = param1 + param2
return result

9. Classes
class Derived(Base):
def Method(self,...):
…
Details: https://docs.python.org/2/tutorial/classes.html

10. Some built-in data types
int, float, long, complex, string, file
Lists: [ 1, “string”, 2.3 ]
Dictionaries: { “Kate”:33 , “John”:25, “Deanna”:42 }
Sets: set([1,2,1,6,7]) → [1,2,6,7]
Tuple: (1, “Nigel”, 23)
Details: https://docs.python.org/2/library/stdtypes.html

11. Immutable objects
Cannot be changed after creation.
Examples: numbers, strings, tuples (the minority)
x = some immutable object
y = x
y = … # change value of y
x has the same value
Details: https://docs.python.org/2/reference/datamodel.html and Please read [2]

12. Immutable objects (2)
>>> x=39
>>> y=x
>>> y=41
>>> print(x)
39
>>> s1='Rob the bank!'
>>> s2=s1
>>> s2='Then take me home'
>>> print(s1)
Rob the bank!
>>> s="It's Python, ... yo!"
>>> s[2]='a'
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
TypeError: 'str' object does not support item assignment

13. Mutable objects
Can be changed after creation
Examples: lists, dictionaries, classes (the majority)
x = some mutable object
y = x
y = … # change value of y
x has changed its value

14. Mutable objects (2)
>>> d1={"Deanna":"Nick Cave", "Jackie":"Placebo"}
>>> d2=d1
>>> d2["Jackie"]="Sinead O'Connor"
>>> print(d1)
{'Deanna': 'Nick Cave', 'Jackie': "Sinead O'Connor"}
>>> a1=['The Mono Jacks', 'Grimus', 'Urma']
>>> a2=a1
>>> a2.append('Byron')
>>> print(a1)
['The Mono Jacks', 'Grimus', 'Urma', 'Byron']

15. Some popular internal modules
Full list here https://docs.python.org/2.7/py-modindex.html
Coverage:
● process/thread management - threading, subprocess
● serialization/persistence - pickle, sqlite3, struct, bsddb, minidom
● network communication - smtplib, poplib, ftplib, sockets, httplib,
urllib2, asyncore
● encoding/compression - bz2, zlib, tarfile, zipfile, base64
● file/directory handling - os, tempfile, os.path, stat
● security - ssl, md5
● string matching/parsing - re, fnmatch, ast

16. Some listed here: https://wiki.python.org/moin/UsefulModules
Coverage:
● database handling - sqlalchemy, mysql-python
● GUI - wxpython, pyqt
● Scientific/Math functionality - NumPy, SciPy
● Web development - django, web2py
● Image processing - pil, pyqtgraph
● Networking - tornado, twisted, Gevent
● Process listing and manipulation - psutil
Some popular external modules

17. Enough, let’s walk the talk!

18. Code for this presentation
https://github.com/undergraver/PythonPresentation/
01_intro - some of Python’s characteristics
02_typical - common Python usages
03_demo - few polished examples
04_regex - regular expressions in Python

19. Notes for examples
Please read the documentation for each python module used. Start from [3]
wxpythonUI uses wxpython [5] python library + wxformbuilder [7] for ui
design
process list/kill uses psutil [6] python library
For regex is is recommended to read the documentation ( [4] )

20. Notable applications using Python

21. References
[1] https://developers.google.com/edu/python/
[2] http://www.slideshare.net/amiable_indian/introduction-to-python
[3] https://docs.python.org/
[4] https://docs.python.org/2/library/re.html
[5] http://www.wxpython.org/
[6] https://code.google.com/p/psutil/
[7] http://sourceforge.net/projects/wxformbuilder/