56 lines
1.7 KiB
Python
56 lines
1.7 KiB
Python
# cta.py
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from collections import defaultdict, Counter
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import tracemalloc
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import readrides
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tracemalloc.start()
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rows = readrides.read_rides_as_dicts('../../Data/ctabus.csv')
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# --------------------------------------------------
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# Question 1: How many bus routes are in Chicago?
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# Solution: Use a set to get unique values.
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routes = set()
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for row in rows:
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routes.add(row['route'])
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print(len(routes), 'routes')
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# --------------------------------------------------
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# Question 2: How many people rode route 22 on February 2, 2011?
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# Solution: Make dictionary with composite keys
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by_route_date = { }
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for row in rows:
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by_route_date[row['route'], row['date']] = row['rides']
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print('Rides on Route 22, February 2, 2011:', by_route_date['22','02/02/2011'])
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# --------------------------------------------------
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# Question 3: Total number of rides per route
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# Solution: Use a counter to tabulate things
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rides_per_route = Counter()
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for row in rows:
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rides_per_route[row['route']] += row['rides']
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# Make a table showing the routes and a count ranked by popularity
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for route, count in rides_per_route.most_common():
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print('%5s %10d' % (route, count))
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# --------------------------------------------------
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# Question 4: Routes with greatest increase in ridership 2001 - 2011
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# Solution: Counters embedded inside a defaultdict
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rides_by_year = defaultdict(Counter)
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for row in rows:
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year = row['date'].split('/')[2]
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rides_by_year[year][row['route']] += row['rides']
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diffs = rides_by_year['2011'] - rides_by_year['2001']
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for route, diff in diffs.most_common(5):
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print(route, diff)
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# ---- Memory use
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print('Memory Use: Current %d, Peak %d' % tracemalloc.get_traced_memory())
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