Agenda Announcements List comprehension Set Password example - - PowerPoint PPT Presentation

Agenda

• Announcements
• List comprehension
• Set
• Password example

1/14/2013 CompSci101 Peter Lorensen 1

List comprehension [ [

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]

[ element for element in sequence if element ]

for loop if x

pay = [850.0, 1250.0, 900.0, 1400.0, 1100.0] lowPay = [ pay for pay in salary if pay < 1000.00 ] >>[ 850.0, 900.0 ]

Set

• Set is similar to a list, but can only have unique

elements.

• Set are unordered. No index.
• Use set() or set(list) to create a set. Then add.

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passengers = set([“John”, “Bob”, “Lisa”]) passengers.add(“peter”) >> set([“John”, “Bob”, “Lisa”, “peter”])

Set

We often use for comparison

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Operation Function Short Union set1.union( set2 ) | Intersection set1.intersection( set2 ) & Difference set1.difference( set2 )

• Symmetric

difference set1.symmetric_differe nce( set2 ) ^

Daphne Koller

Computers learn to diagnose breast cancer?

• AI and Machine Learning

– http://www.youtube.com/watch?v=DX2_9ntOcQI – http://med.stanford.edu/ism/2011/november/compu ter.html

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"But to practice problem-solving, a student must first master certain concepts. By providing a cost-effective solution for this first step, we can focus precious classroom time on more interactive problem-solving activities that achieve deeper understanding — and foster creativity." Coursera Founder, NY Times, December 5, 2011

1/14/2013 CompSci101 Peter Lorensen 6

12 MILLION 2011

Passwords

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http://zd.net/ME10pW http://bit.ly/XSGIaT http://on.mash.to/MjlDRs http://bit.ly/YPlrWn

Passwords

Troy Hunt analysis of leaked Sony password

(http://bit.ly/kr2jpL):

• People re-use their passwords on different sites.

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“The only secure password is the one you cant remember”

(http://bit.ly/hhwE4n)

Duke IT Strategies for good passwords

Use lines from a childhood verse: Verse Line: Yankee Doodle went to town Password: YDwto#town Use lines from a favorite song: Lyric: How Much is that Doggie in the Window? Password: H$itditw? City Expression: Chicago is my kind of town Password: CimYKot! Foods disliked during childhood: Food: rice and raisin pudding Password: ric&raiPudng

Note: Obviously, you shouldn't use any of the passwords used as examples in this document. Treat these examples as guidelines only.

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Peter Lorensen 9

Password lists on the Internet

1/14/2013 CompSci101 Peter Lorensen 10

• Accessible list of passwords on the Internet:

https://dazzlepod.com/site_media/txt/passwords.txt

• Disclosure Project

by Dazzlepod “The disclosures on this website have been made available publicly so that users can find out if they were exposed as a result of the releases made by hackers.”

(https://dazzlepod.com/disclosure/)