Question

1. Code is already written please show all outputs and comment on function of code.

2. These are Python 3 programs. Please show outpouts and comment on fuctions.

Note: this is a bit of a “backwards” exercise – we show you code, you figure out what it does.

As a result, not much to submit – don’t worry about it – you’ll have a chance to use these in other exercises.

>>> feast = ['lambs', 'sloths', 'orangutans',
             'breakfast cereals', 'fruit bats']

>>> comprehension = [delicacy.capitalize() for delicacy in feast]

What is the output of:

>>> comprehension[0]
???

>>> comprehension[2]
???

(figure it out before you try it)

Filtering lists with list comprehensions

>>> feast = ['spam', 'sloths', 'orangutans', 'breakfast cereals',
            'fruit bats']

>>> comp = [delicacy for delicacy in feast if len(delicacy) > 6]

What is the output of:

>>> len(feast)
???

>>> len(comp)
???

(figure it out first!)

Unpacking tuples in list comprehensions

>>> list_of_tuples = [(1, 'lumberjack'), (2, 'inquisition'), (4, 'spam')]

>>> comprehension = [ skit * number for number, skit in list_of_tuples ]

What is the output of:

>>> comprehension[0]
???

>>> len(comprehension[2])
???

Double list comprehensions

>>> eggs = ['poached egg', 'fried egg']

>>> meats = ['lite spam', 'ham spam', 'fried spam']

>>> comprehension = \
[ '{0} and {1}'.format(egg, meat) for egg in eggs for meat in meats]

What is the output of:

>>> len(comprehension)
???

>>> comprehension[0]
???

Set comprehensions

>>> comprehension = { x for x in 'aabbbcccc'}

What is the output of:

>>> comprehension
???

Dictionary comprehensions

>>> dict_of_weapons = {'first': 'fear',
                       'second': 'surprise',
                       'third':'ruthless efficiency',
                       'forth':'fanatical devotion',
                       'fifth': None}
>>> dict_comprehension = \
{ k.upper(): weapon for k, weapon in dict_of_weapons.items() if weapon}

What is the output of:

>>> 'first' in dict_comprehension
???
>>> 'FIRST' in dict_comprehension
???
>>> len(dict_of_weapons)
???
>>> len(dict_comprehension)
???

Answer 1

Code:

import os
import sys

feast = ['lambs', 'sloths', 'orangutans','breakfast cereals', 'fruit bats']
comprehension = [delicacy.capitalize() for delicacy in feast]
print comprehension[0]
print comprehension[2]

feast = ['spam', 'sloths', 'orangutans', 'breakfast cereals','fruit bats']
comp = [delicacy for delicacy in feast if len(delicacy) > 6]
print len(feast)
print len(comp)
list_of_tuples = [(1, 'lumberjack'), (2, 'inquisition'), (4, 'spam')]
comprehension = [ skit * number for number, skit in list_of_tuples ]
print comprehension[0]
print len(comprehension[2])
eggs = ['poached egg', 'fried egg']
meats = ['lite spam', 'ham spam', 'fried spam']
comprehension = [ '{0} and {1}'.format(egg, meat) for egg in eggs for meat in meats]
print len(comprehension)
print comprehension[0]
comprehension = { x for x in 'aabbbcccc'}
print comprehension

output:

Lambs
Orangutans
5
3
lumberjack
16
6
poached egg and lite spam
set(['a', 'c', 'b'])