import time
# dictionary with questions and answer 
q_a = {
    'Q 1: Which data structure is immutable?': ['A: tulip',
                                               'B: tuple', 
                                               'C: tumble', 
                                               'B'],
    'Q 2: Which data structure does not allow duplicate objects?': ['A: set',
                                                                   'B: list',
                                                                   'C: dictionary',
                                                                   'A'],
    'Q 3: How do you sort a dictionary?':['A: sort(dict)',
                                         'B: sorted(dict)',
                                         'C: dict.sorted',
                                         'B'],
    'Q 4: How do you remove the 5 from list = [5,6,7,8]?': ['A: list.remove(0)',
                                                           'B: list.remove(5)',
                                                           'C: list.remove(1)',
                                                           'B'],
    'Q 5: Which keyword do you use to loop over a given list of elements?': ['A: for',
                                                                            'B: while',
                                                                            'C: loop',
                                                                            'A'],                                                              
    'Q 6: Which command do you use to access modules?':['A: load',
                                                       'B: source',
                                                       'C: import',
                                                       'C'],
    'Q 7: What characterises suits of code?':['A: indentation and preceding colon',
                                             'B: curved brackets and preceding colon',
                                             'C: indentation followed by semicolon',
                                             'A'],
    'Q 8: How do you get to a function\'s documentation?':['A: help(function_name)',
                                                          'B: help.function_name',
                                                          'C: ?function_name',
                                                          'A'],
    'Q 9: What is an object in Python?':['A: data structures and variables',
                                        'B: data structures and functions',
                                        'C: everything',
                                        'C'],
    'Q10: What does found={} represents?':['A: an empty set',
                                           'B: an empty dictionnary',
                                           'C: both an empty set or an empty dictionnary',
                                           'B'],
    'Q11: Which keyword do you use to name a function?':['A: function',
                                                         'B: def',
                                                         'C: fun',
                                                         'B'],
    'Q12: How do you add a multiline comment in your programm?':['A: """ comment """',
                                                                 'B: # comment',
                                                                 'C: # comment #',
                                                                 'A'],
    'Q13: What does not hold for Python?':['A: Don\'t mix tabs with spaces in your Python code.',
                                           'B: A few lines of code do a lot.',
                                           'C: Don\'t mix and match the data structures.',
                                           'C',
                                           'end']}
# set of valid answers
set_answer = {'A','B','C'}
# initialise num_correct=number of correct answers
num_correct = 0
# loop across questions (sorted)
for k, v in sorted(q_a.items()):
    # print question
    print(k)
    # print possible answers
    for i in range(3):
        print(v[i])
    # ask for answer
    answer = input('Please choose your answer (A,B or C):')
    # check if answer is valid (loop until answer is valid):
    while answer not in set_answer:
        answer = input('This answer is invalid. Please choose A, B or C:')
    # check if answer is correct:
    if answer == v[3]:
        print('Correct!')
        num_correct = num_correct + 1
    else:
        print('Not correct. The correct answer is ', v[3],'.')
    time.sleep(1)
    print()
    if len(v) == 4:
        input('Please press Enter to continue.')
        print()
# final quiz result
print('You answered', num_correct, 'of', len(q_a), 'questions correctly.')
if num_correct/len(q_a) < 0.33:
    print('Perhaps you should read the book again.')
elif num_correct/len(q_a) <0.6:
    print('Not bad, but you might want to re-read some sections of the book.')
elif num_correct/len(q_a) >0.9:
    print('You\'re an expert!')
else:
    print('Well done!')
time.sleep(3)
print()
input('Please press Enter to exit the programme.')