comment

import csv, urllib

def load_csv(url): d = {} fp = urllib.urlopen(url) for row in csv.DictReader(fp): key = row['date'] value = row['fish']

 x = d.get(key, [])
 x.append(value)
 d[key] = x

return d

def make_dates_dict(fish_d): dates_d = {} for key in fish_d: for fish in fish_d[key]: dates_d[fish] = [] for fish in dates_d: for key in fish_d: for fishname in fish_d[key]: if fishname == fish: dates_d[fish].append(key) dates_d[fish] = set(dates_d[fish])

write code HERE to fill in dates_d

note, fish_d is a dictionary created by load_csv where the

KEYS are dates and the VALUES are lists of fish. from

csv.DictReader. so, fish_d[date] is a list of fish from that

day.

the return value, 'dates_d', should be a dictionary where the

KEYS are fish and the VALUES are lists of dates.

return dates_d

def get_fishes_by_date(fish_d, date): fishlist = fish_d.get(date)

write code HERE to fill in fishlist

return fishlist

def get_dates_by_fish(dates_d, fish): dateslist = dates_d.get(fish)

write code HERE to fill in dateslist

note, dates_d is a dictionary created by make_dates_dict; see the

comment there for more info.

return dateslist

this code is outside the functions and USES the functions to

load data and ask questions of the data.

def get_fishes_by_datelist(fish_d, datelist): fish_on_datelist = [] for date in datelist: for key in fish_d: if key == date: for fish in fish_d[key]: fish_on_datelist.append(fish) return fish_on_datelist

def get_dates_by_fishlist(dates_d, fishlist): dates_on_fishlist = [] for fish in fishlist: for key in fish_d: for fishy in fish_d[key]: if fish == fishy: dates_on_fishlist.append(key) dates_on_fishlist_set = set(dates_on_fishlist) return dates_on_fishlist_set

fish_d = load_csv('https://raw.github.com/ctb/edda/master/doc/beacon-2011/tutorial5/fishies.csv') dates_d = make_dates_dict(fish_d)

print get_fishes_by_date(fish_d, '12/5')

print get_dates_by_fish(dates_d, 'cod')

datelist = ['11/3', '11/4'] fishlist = ['cod', 'sole'] henry = get_fishes_by_datelist(fish_d, datelist) frank = get_dates_by_fishlist(dates_d, fishlist) print frank