49 lines
1.6 KiB
Python
49 lines
1.6 KiB
Python
# A dictionary is a data type similar to arrays, but works with keys and values instead of indexes. Each value stored in a dictionary can be accessed using a key, which is any type of object (a string, a number, a list, etc.) instead of using its index to address it.
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# For example, a database of phone numbers could be stored using a dictionary like this:
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phonebook = {}
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phonebook["John"] = 938477566
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phonebook["Jack"] = 938377264
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phonebook["Jill"] = 947662781
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print(phonebook)
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#Alternatively, a dictionary can be initialized with the same values in the following notation:
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phonebook = {
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"John" : 938477566,
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"Jack" : 938377264,
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"Jill" : 947662781
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}
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print(phonebook)
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#Dictionaries can be iterated over, just like a list. However, a dictionary, unlike a list, does not keep the order of the values stored in it. To iterate over key value pairs, use the following syntax:
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for name, number in phonebook.items():
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print("Phone number of %s is %d" % (name, number))
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#To remove a specified index, use either one of the following notations:
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del phonebook["John"]
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print(phonebook)
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phonebook["John"] = 938477566 #To add it back in
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#alternative solution:
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phonebook.pop("John")
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print(phonebook)
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# Exercise
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# Add "Jake" to the phonebook with the phone number 938273443, and remove Jill from the phonebook.
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phonebook = {
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"John" : 938477566,
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"Jack" : 938377264,
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"Jill" : 947662781
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}
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# your code goes here
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phonebook["Jake"] = 938273443
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del phonebook["Jill"]
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# testing code
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if "Jake" in phonebook:
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print("Jake is listed in the phonebook.")
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if "Jill" not in phonebook:
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print("Jill is not listed in the phonebook.") |