5 Examples of Using Dict Comprehension in Python to Simplify Your Code
Python is one of the most popular programming languages for its simplicity and readability. One feature that can make your code easier to read and write is dictionary comprehension. By using dict comprehension, you can create Python dictionaries in a more concise and readable way. In this article, we’ll explore five examples of using dict comprehension in Python to simplify your code.
Example 1: Dictionary Comprehension for Squaring Numbers
Suppose you have a list of numbers and you want to create a dictionary where the key is the number and the value is the square of that number. This is a one-liner that can be easily achieved using dictionary comprehension.
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numbers = [1, 2, 3, 4, 5]
squares = {num: num*num for num in numbers}
print(squares)
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The output will be:
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{1: 1, 2: 4, 3: 9, 4: 16, 5: 25}
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Example 2: Creating a Dictionary from Two Lists
Suppose you have two lists, one containing the keys and the other containing the values. You can use dictionary comprehension to create a dictionary from these two lists.
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keys = [‘a’, ‘b’, ‘c’]
values = [1, 2, 3]
dictionary = {keys[i]: values[i] for i in range(len(keys))}
print(dictionary)
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The output will be:
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{‘a’: 1, ‘b’: 2, ‘c’: 3}
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Example 3: Filtering a Dictionary using Comprehension
Suppose you have a dictionary containing student names and their grades, and you want to create a new dictionary with only those students who have scored above a certain grade. You can use dictionary comprehension to achieve this in just one line.
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students = {‘John’: 85, ‘Mark’: 65, ‘Kate’: 90, ‘Emma’: 75}
passing_students = {s: students[s] for s in students if students[s] >= 80}
print(passing_students)
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The output will be:
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{‘John’: 85, ‘Kate’: 90}
“`
Example 4: Dictionary Comprehension with Conditional Statements
Suppose you have a dictionary and you want to create a new dictionary with only those keys that satisfy a certain condition. You can use dictionary comprehension with conditional statements to achieve this.
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original_dict = {‘a’: 1, ‘b’: 2, ‘c’: 3, ‘d’: 4}
new_dict = {k: original_dict[k] for k in original_dict if k in [‘a’, ‘c’]}
print(new_dict)
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The output will be:
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{‘a’: 1, ‘c’: 3}
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Example 5: Nested Dictionary Comprehension
Suppose you have two nested lists and you want to create a nested dictionary from them. You can use nested dictionary comprehension to achieve this.
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foods = [‘pizza’, ‘burger’, ‘taco’]
prices = [10, 8, 6]
food_dictionary = {food: { ‘price’: prices[i], ‘index’: i } for i, food in enumerate(foods)}
print(food_dictionary)
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The output will be:
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{‘pizza’: {‘price’: 10, ‘index’: 0}, ‘burger’: {‘price’: 8, ‘index’: 1}, ‘taco’: {‘price’: 6, ‘index’: 2}}
“`
Conclusion
Using dictionary comprehension in Python, you can simplify your code and achieve the same results with fewer lines of code. It can also make your code more readable and easier to maintain. The five examples discussed here demonstrate the versatility and power of dictionary comprehension in Python. By understanding and using this feature, you can become a more effective and efficient Python programmer.
