Simple examples of python code implementing "hello world". Given at the first Memphis Python User group meeting (2011-11-21).

1. Welcome to MEMpy
Brad Montgomery
http://mempy.org

2. print('hello world')

3. Python
• multi-platform
• multi-paradigm
• dynamically-typed
• big standard lib (tons of 3rd party libs)
• open source
• by Guido van Rossum (BDFL)

4. the interpreter
• An interactive Python shell
• In a *nix environment, open a terminal and
type: python
• In Windows, run IDLE

5. IDLE

6. the interpreter
>>> print('hello world')
hello world
>>> 31 + 11
42
>>>

7. functions
# save this in a file named "greeting.py"
def hello(input_name='world'):
greeting = "Hello {name}".format(
name=input_name)
return greeting
>>> from greeting import hello
>>>
>>> hello()
'Hello world'
>>>
>>> hello("Universe")
'Hello Universe'

8. modules/packages
• namespaces!
• module: a file with python code:
greeting.py
• package: a directory of python modules

9. modules/packages
>>> from greetingapp import greeting
>>>
>>> greeting.hello()
'Hello world'
>>>
>>> greeting.hello("Universe")
'Hello Universe'

10. classes
class Greeter(object):
names = ['World' ]
def hello(self, names=None):
if names:
self.names = names
for name in self.names:
s = 'Hello {n}'.format(n=name)
print(s)

11. classes
>>> from greeting import Greeter
>>> g = Greeter()
>>> g.hello()
Hello World
>>> g.hello(['Bill', 'Betty'])
Hello Bill
Hello Betty
>>>

12. who’s using python?
• Google • EDU’s
• YouTube • CERN
• Nasa • ESRI
• Astra-Zeneca • CCP Games
• Lucasfilm • Silicon Valley Startups
• Reddit • Hobbyists

13. learn more
• http://learnpythonthehardway.org/
• http://openbookproject.net/thinkCSpy/
• http://docs.python.org/tutorial/