Lambda functions are defined as follows:
lambda (parameter list) : (return function)
>>>addTwoNumbers = lambda x,y : x + y
>>>addTwoNumbers(5,10)
15
>>>
>>>addFive = lambda x : x + 5
>>>addFive(1)
6
>>>printResults = lambda func, val : print(func(val))
>>>
>>>printResults(addFive, 1)
6
>>>fruits=['watermelon','Apple','mango','KIWI','aprcot','LEMON','guava']
>>> sorted_fruits = sorted(fruits, key=lambda e: e.lower())
>>> sorted_fruits
['Apple', 'aprcot', 'guava', 'KIWI', 'LEMON', 'mango', 'watermelon']