Python Lambda expressions: Make code concise and clear

Introduction to Lambda expressions

Lambda expression is an anonymous function in python. It can define a function without defining a function name. The syntax is:

lambda arguments : expression

Among them, arguments are the parameters of the function, and expression is the expression of the function. For example, the following code defines a lambda expression that adds two numbers and returns the result:

lambda x, y: x + y

Advantages of Lambda expressions

The main advantages of Lambda expressions are simplicity and anonymity. It lets you define a function without defining its name, which is useful for some simple tasks. For example, the following code uses a lambda expression to square each element in a list:

numbers = [1, 2, 3, 4, 5]
squared_numbers = map(lambda x: x ** 2, numbers)
print(list(squared_numbers))

The output result is:

numbers = [1, 2, 3, 4, 5]
even_numbers = filter(lambda x: x % 2 == 0, numbers)
print(list(even_numbers))

The output result is:

[2, 4]

• List mapping: Each element in a list can be easily mapped to a new value using lambda expressions. For example, the following code uses a lambda expression to square each element in the list:

numbers = [1, 2, 3, 4, 5]
squared_numbers = map(lambda x: x ** 2, numbers)
print(list(squared_numbers))

The output result is:

strings = ["apple", "banana", "cherry", "durian", "elderberry"]
sorted_strings = sorted(strings, key=lambda x: len(x))
print(sorted_strings)

The output result is:

["apple", "cherry", "banana", "elderberry", "durian"]

Conclusion

Lambda expressions are a powerful tool that allows you to write cleaner, more readable, and more efficient code. It can be used in a variety of scenarios, including operations such as list filtering, mapping, and sorting. If you want to write cleaner and more efficient code, lambda expressions are a tool worth mastering.

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