wk 10 - quiz.py

__author__ = 'edwardlau'
"""
Question 1
What is the difference between a Python tuple and Python list?
Lists are mutable and tuples are not mutable
Tuples can be expanded after they are created and lists cannot
Lists maintain the order of the items and tuples do not maintain order
Lists are indexed by integers and tuples are indexed by strings
"""

# Answer: Lists are mutable and tuples are not mutable

"""
Question 2
Which of the following methods work both in Python lists and Python tuples?
reverse()
sort()
append()
pop()
index()
"""

# Answer: index()

"""
Question 3
What will end up in the variable y after this code is executed?
x , y = 3, 4
3
A two item tuple
4
A dictionary with the key 3 mapped to the value 4
A two item list
"""

# Answer: 4


"""
Question 4
In the following Python code, what will end up in the variable y?
x = { 'chuck' : 1 , 'fred' : 42, 'jan': 100}
y = x.items()
A list of integers
A list of strings
A list of tuples
A tuple with three integers
"""

# Answer: A list of tuples


"""
Question 5
Which of the following tuples is greater than x in the following Python sequence?
x = (5, 1, 3)
if ??? > x :
   ...
(6, 0, 0)
(4, 100, 200)
(5, 0, 300)
(0, 1000, 2000)
"""

# Answer: (6,0,0)

"""
Question 6
What does the following Python code accomplish, assuming the c is a non-empty dictionary?
tmp = list()
for k, v in c.items() :
    tmp.append( (v, k) )
It sorts the dictionary based on its key values
It creates a list of tuples where each tuple is a value, key pair
It computes the largest of all of the values in the dictionary
It computes the average of all of the values in the dictionary
"""

# Answer: It creates a list of tuples where each tuple is a value, key pair

"""
Question 7
If the variable data is a Python list, how do we sort it in reverse order?
data = data.sort(-1)
data.sort(reverse=True)
data.sort.reverse()
data = sortrev(data)
"""

# Answer: data.sort(reverse=True)

"""
Question 8
Using the following tuple, how would you print 'Wed'?
days = ('Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat', 'Sun')
print days[1]
print days(2)
print days{2}
print days.get(1,-1)
print days[2]
"""

# Answer: print days[2]

"""
Question 9
In the following Python loop, why are there two iteration variables (k and v)?
c = {'a':10, 'b':1, 'c':22}
for k, v in c.items() :
    ...
Because for each item we want the previous and current key
Because the items() method in dictionaries returns a list of tuples
Because there are two items in the dictionary
Because the keys for the dictionary are strings
"""

# Answer: Because the items() method in dictionaries returns a list of tuples

"""
Question 10
Given that Python lists and Python tuples are quite similar - when might you prefer to use a tuple over a list?
For a list of items that want to use strings as key values instead of integers
For a list of items that will be extended as new items are found
For a temporary variable that you will use and discard without modifying
For a list of items you intend to sort in place
"""

# Answer: For a temporary variable that you will use and discard without modifying