In this Python Dictionary article we want to talk about Ultimate Guide to Python Dictionary Cheat Sheet, Python Dictionaries are powerful data structure in Python that allows you to store data in key value pairs. they are useful in different programming tasks from data analysis to web development. in this article we want to provide you with an ultimate Python dictionary cheat sheet that will help you get started with dictionaries and get the most out of them.
Dictionaries are created using curly braces {}. this is is an example of a dictionary that maps strings to integers.
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my_dict = {"apple": 5, "banana": 10, "orange": 15} |
For accessing the value of a key in dictionary, you can use square bracket [] notation like this.
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my_dict = {"apple": 5, "banana": 10, "orange": 15} print(my_dict["apple"]) |
This will be the result
If the key does not exist in the dictionary, you will get a KeyError. to avoid this, you can use get() method like this.
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my_dict = {"apple": 5, "banana": 10, "orange": 15} print(my_dict.get("apple", 0)) print(my_dict.get("peach", 0)) |
For adding new key value pair to a dictionary, you can use square bracket [] notation like this.
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my_dict = {"apple": 5, "banana": 10, "orange": 15} my_dict["geekscoders.com"] = 20 print(my_dict) |
This will be the result and we have added a new item of geekscoders.com to Python Dictionary.
For updating value of a key in a dictionary, you can use square bracket [] notation.
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my_dict = {"apple": 5, "banana": 10, "orange": 15} my_dict["apple"] = 8 print(my_dict) |
Also you can remove key value pair from dictionary, to remove a key value pair from a dictionary, you can use del keyword.
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my_dict = {"apple": 5, "banana": 10, "orange": 15} del my_dict["apple"] print(my_dict) |
This will be the result
Dictionaries in Python have several useful methods that makes them even more powerful.
keys() method returns a list of all the keys in the dictionary:
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my_dict = {"apple": 5, "banana": 10, "orange": 15} print(my_dict.keys()) # Output: ["apple", "banana", "orange"] |
values() method returns a list of all the values in the dictionary:
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my_dict = {"apple": 5, "banana": 10, "orange": 15} print(my_dict.values()) # Output: [5, 10, 15] |
items() method returns a list of tuples, where each tuple contains a key value pair:
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my_dict = {"apple": 5, "banana": 10, "orange": 15} print(my_dict.items()) # Output: [("apple", 5), ("banana", 10), ("orange", 15)] |