Python and R are becoming the defacto tools for data scientists. What is Python, who is using it, and why should a statistician care?

1. Why Python? (For Stats
People)
@__mharrison__
© 2013

2. About Me
●
●
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12+ years Python
Worked in Data Analysis, HA, Search,
Open Source, BI, and Storage
Author of multiple Python Books

3. Book

4. Book
Treading on Python Volume 1 meant to
make people proficient in Python quickly

5. Why Python?

6. General Purpose Language
“I’d rather do math in a general-purpose
language than do general-purpose
programming in a math language.”
John D Cook

7. Who's Using Python?
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Startups (on HN)
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Data Scientists (Strata)
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Big Companies

8. Who
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Google
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Nasa
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ILM
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Redhat
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Finance
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Instagram
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Pinterest
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Youtube
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...

9. Open Source
Free in both senses of the word

10. Batteries Included
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Text
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Network
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JSON
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Command Line
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Files
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XML

11. Large Community
PyPi - PYthon Package Index
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Web
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Database
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GUI
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Scientific
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Network Programming
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Games

12. Large Community
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User Groups
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PyLadies
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Conferences

13. Local
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utahpython.org - 2nd Thurs. 7pm
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Utah Open Source Conference

14. Tooling
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Editors
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Testing
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Profiling
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Debugging
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Documentation

15. Optimizes for Programmer Time
“We should forget about small
efficiencies, say about 97% of the time:
premature optimization is the root of
all evil.”
Donald Knuth

16. Executable Pseudocode
function quicksort(array)
if length(array) ≤ 1
return array // an array of zero or one elements is already sorted
select and remove a pivot element pivot from 'array' // see '#Choice of
pivot' below
create empty lists less and greater
for each x in array
if x ≤ pivot then append x to less'
else append x to greater
return concatenate(quicksort(less), list(pivot), quicksort(greater)) //
two recursive calls
http://en.wikipedia.org/wiki/Quicksort

17. Executable Pseudocode
>>> def quicksort(array):
...
if len(array) <= 1:
...
return array
...
pivot = array.pop(len(array)/2)
...
lt = []
...
gt = []
...
for item in array:
...
if item < pivot:
...
lt.append(item)
...
else:
...
gt.append(item)
...
return quicksort(lt) + [pivot] + quicksort(gt)

18. But...
Python has Timsort. Optimized for real
world (takes advantage of inherent order)
and written in C. (Stolen by Java,
Android, and Octave)

19. Multi-paradigm Languange
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Imperative
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Object Oriented
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Functional

20. Imperative
>>> def sum(items):
...
total = 0
...
for item in items:
...
total = total + item
...
return total
>>> sum([2, 4, 8])
14

21. OO
>>> class Summer:
...
def __init__(self):
...
self.items = []
...
def add_item(self, item):
...
self.items.append(item)
...
def sum(self):
...
return sum(self.items)
>>>
>>>
>>>
>>>
5
s = Summer()
s.add_item(2)
s.add_item(3)
s.sum()

22. Functional
>>> import operator
>>> sum = lambda x: reduce(operator.add, x)
>>> sum([4, 8, 22])
34

23. Why Not Python?

24. Slow
Sometimes you have to optimize. Good C
integration

25. If it ain't broke don't fix it
Don't replace existing solutions for fun

26. R has more depth
Though Python is catching up in some
areas

27. Going Forward

28. IPython Notebook
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Notebook w/ integrated graphs

29. Libraries
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Numpy - matrix math
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scipy - scientific libraries
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scipy.stats - stats
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statsmodel - modeling
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pandas - dataframe
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matplotlib - graphing
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scikit.learn - ml

30. That's all
Questions? Tweet me
For beginning Python secrets see
Treading on Python Volume 1
@__mharrison__
http://hairysun.com