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78 lines
1.8 KiB
78 lines
1.8 KiB
from collections import defaultdict
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stocks = {"GOOG": (613.30, 625.86, 610.50),
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"MSFT": (30.25, 30.70, 30.19)}
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# different possibilities to get values from the dictionary
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print("GOOG: {}".format(stocks["GOOG"]))
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print("RIM: {}".format(stocks.get("RIM", "NOT FOUND")))
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stocks.setdefault("RIM", (67.38, 68.48, 67.28))
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print("RIM: {}".format(stocks["RIM"]))
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for stock, values in stocks.items():
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print("{} last value is {}".format(stock, values[0]))
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random_keys = {}
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random_keys["astring"] = "somestring"
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random_keys[5] = "aninteger"
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random_keys[25.2] = "floats work too"
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random_keys[("abc", 123)] = "so do tuples"
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class AnObject(object):
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def __init__(self, avalue):
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self.avalue = avalue
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my_object = AnObject(14)
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random_keys[my_object] = "We can even store objects"
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my_object.avalue = 12
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try:
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random_keys[[1, 2, 3]] = "We can't store lists though"
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except:
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print("unable to store list \n")
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for key, value in random_keys.items():
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print("{} has value {}".format(key, value))
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if hasattr(key, "avalue"):
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print("{}.avalue ={}".format(key, key.avalue))
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def letter_frequency(sentence):
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frequencies = {}
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for letter in sentence:
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frequency = frequencies.setdefault(letter, 0)
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frequencies[letter] = frequency + 1
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return frequencies
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print(letter_frequency("Hello world, what's going on?"))
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# defaultdict using built-in function
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def letter_frequency_defdict(sentence):
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frequencies = defaultdict(int)
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for letter in sentence:
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frequencies[letter] += 1
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return frequencies
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print(letter_frequency_defdict("Hello world, what's going on?"))
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# defaultdict using self defined function
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num_items = 0
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def tuple_counter():
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global num_items
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num_items += 1
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return num_items, []
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d = defaultdict(tuple_counter)
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d['a'][1].append("hello")
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d['b'][1].append("world")
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print(d)
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