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Learning Objectives

  • Lambda function

  • Map and Lambda

  • Filter and Lambda

Earlier Function

  • Earlier, we used the 'def' keyword to define a function
  • And in the body of the function, we added the logic of the function
  • A lambda function is an anonymous function. Now, what is an anonymous function? An anonymous function is a function that is defined without any name.
  • For example, we defined a function in the earlier topic that can be called whenever required with a name 'even()', the map function can be called using the name' map()' while lambda functions cannot be called whenever required. We define the lambda function whenever needed.
  • The lambda function can take any number of arguments but only has one expression. Let's understand through examples.

Syntax

1 lambda arguments: expression

For example, we had defined a function to calculate the square of the number. We used the map function to get the list of squares of the numbers in a list.

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As mentioned earlier, the lambda function can take any number of arguments. Let's calculate the element-wise sum of two lists.

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Try It Yourself

Can you filter out the even numbers from the list, l1 = [5, 7, 8, 10, 11, 13, 15, 16, 17, 19, 20] using lambda function? Think ???? and write a Python program to filter out the even numbers before continuing.

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The above code can also be written as:

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