Transcript Post Midterm, Compsci 6, Fall 2010 Current tools for structuring data

Post Midterm, Compsci 6, Fall 2010
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Current tools for structuring data
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Current tools for organizing code
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Types: int, boolean, string, float, list, file, tuple
This week and next: set and dictionary collections
Modules, functions, for loop, selection
This week and next: while loop
Why do we study tools for programming?
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Facilitates solving problems in a variety of settings
Compsci 06/101, Fall 2010
8.1
What do sets get us?
Finding unique/different words in a file
def listUnique(filename):
file = open(filename)
words = []
for line in file:
for w in line.strip().split():
if not w in words:
words.append(w)
file.close()
return words
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Compsci 06/101, Fall 2010
8.2
What do sets get us?
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Finding unique/different words in a file
def setUnique(filename):
file = open(filename)
words = set()
for line in file:
for w in line.strip().split():
words.add(w)
file.close()
return words
Compsci 06/101, Fall 2010
8.3
Set details and examples
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Set methods (see book)
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add, clear, difference, intersection, issubset, issuperset,
remove, symmetric_difference, union
Short cuts/operators: -, &, <=, >=, |, ^
What are these?
Two-dimensional random walk on a grid
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Why useful?
How to model?
How to view?
Compsci 06/101, Fall 2010
8.4