Question

2. Consider the following function

# listOfNumbers is a list of only numbers
#
def processList(listOfNumbers):
    result = []
    for i in listOfNumbers:
        if i<0 == 0:
            result.append(i*i)
        else:
            result.append((i*i)+1)
    return result

First, study and test processList(listOfNumbers) to determine what it does Then rewrite its body so that it accomplishes the same task with a one-line list comprehension. Thus, the resulting function will have exactly two lines, the def line and a return line containing a list comprehension expression.

3. Implement function processList2(inputList, specialItem, ignoreItems) that returns a new list that contains all the items of inputList (and in the original order) except 1) any that appear in the list ignoreItems, and 2) occurrences of specialItem (if specialItem is not in ignoreItems) should become the string "special" in the new list. Use a one-line list comprehension to construct the new list. Thus, again, the function will have exactly two lines, the def line and a return line containing a list comprehension expression. For example,

>>> processList2([1,2,3,4], 4, [3])
[1, 2, 'special']              
>>> processList2([1,2,3,4,True,'dog'], 4, [3,5,4])
[1, 2, True, 'dog']
>>> processList2([1,1,2,2], 1, [2])
['special', 'special']

Answer 1

# listOfNumbers is a list of only numbers
def processList(listOfNumbers):
    return [i * i if i < 0 else i * i + 1 for i in listOfNumbers]

def processList2(inputList, specialItem, ignoreItems):
    return [item if item != specialItem else 'special' for item in [i for i in inputList if i not in ignoreItems]]


print(processList2([1, 2, 3, 4], 4, [3]))
print(processList2([1, 2, 3, 4, True, 'dog'], 4, [3, 5, 4]))
print(processList2([1, 1, 2, 2], 1, [2]))