02_python_quiz_solution.py

'''
Python quiz: SOLUTION
'''

## SECTION 1:

# 1. How do you create an empty list named mylist?
# Answer: mylist = []
# Alternative: mylist = list()

# 2. Without running the code, what will this return?
5 == 5.0
# Answer: True

# 3. Without running the code, what will this return?
5 > 3 or 5 < 3
# Answer: True

# 4. How do I return the number 50 from this list?
numlist = range(1, 101)
# Answer: numlist[49]

# 5. Without running the code, what will these return?
len(numlist)
# Answer: 100
type(numlist)
# Answer: list



## SECTION 2:

# 6. Divide 3 by 2 and get a result of 1.5
# Answer: 3/float(2)
# Alternative: 3/2.0
# Alternative: from __future__ import division

# 7. Import the math module, and use the sqrt() function to take the square root of 1089.
# Answer: import math
#         math.sqrt(1089)
# Alternative: from math import sqrt
#              sqrt(1089)

# 8. Slice newlist to return a list with the numbers 2, 3, 4:
newlist = [0, 1, 2, 3, 4, 5, 6]
# Answer: newlist[2:5]

# 9. From this dictionary, return the 10, and then change the 30 to a 40.
d = {'a':10, 'b':20, 'c':30}
# Answer part 1: d['a']
# Answer part 2: d['c'] = 40

# 10. Convert this for loop into a "better" for loop that doesn't use the i variable:
fruits = ['apple', 'banana', 'cherry']
for i in range(len(fruits)):
    print fruits[i].upper()
# Answer: for fruit in fruits:
#             print fruit.upper()



## SECTION 3:

# 11. Define a function "calc" that takes two variables, a and b, and returns their sum.
# Answer: def calc(a, b):
#             return a + b

# 12. Join these two lists to make a single list [1, 2, 3, 4]:
list1 = [1, 2]
list2 = [3, 4]
# Answer: list1.append(list2)
# Alternative: list1 + list2
# Note: The first answer modifies list1, whereas the second doesn't modify either list

# 13. Return Brandon's state only:
locations = {'Sinan': ['Baltimore', 'MD'], 'Brandon': ['Arlington', 'VA']}
# Answer: locations['Brandon'][1]

# 14. Without running the code, what will the second line return?
nums = [1, 2, 3]
[num*2 for num in nums]
# Answer: [2, 4, 6]

# 15. Turn this for loop into a list comprehension:
upperfruits = []
for fruit in fruits:
    upperfruits.append(fruit.upper())
# Answer: upperfruits = [fruit.upper() for fruit in fruits]