1.1 What is a Lambda Function?

A lambda function is a small, one-line function that doesn’t need a name. It’s useful for quick,

simple operations.

* syntax lambda arguments: expression

Suppose you want to sort a list of tuples based on the second item in each tuple:

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# List of tuples

data = [(1, ‘apple’), (2, ‘banana’), (3, ‘cherry’), (4, ‘date’)]

# Sort the list of tuples by the second item in each tuple using a lambda␣

↪function

sorted_data = sorted(data, key=lambda x: x[1])

print(sorted_data)

[(1, ‘apple’), (2, ‘banana’), (3, ‘cherry’), (4, ‘date’)]

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• sorted() is used to sort the list.

• key=lambda x: x[1] specifies that the sorting should be based on the second item in each

tuple (the fruit name).

• lambda x: x[1] is a lambda function that takes a tuple x and returns the second element of

that tuple (x[1]).

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