Dictionaries Debugging

• Each of the following short code contains one or more bugs.     

• Please identify and correct these bugs.

• Provide an explanation for your answer.

Question-1

{'A'=1, 'B'=2, 'C'=3}

Solution

For dictionaries, = should be replaced with : to associate keys with values.

Question-2

my_dict = {'A':70, 'B':90, 'C':75, 'D':80}
my_dict('C')

Solution

my_dict(‘C’) must be my_dict[‘C’].

Question-3

my_dict = ['A':70, 'B':90, 'C':75, 'D':80]
my_dict['C']

Solution

To construct a dictionary in Python, curly braces {} must be used instead of square brackets [].

Question-4

stock_dict = {'day-1':{'High': 70, 'Low':62, 'Close':65},
              'day-2':{'High': 68, 'Low':60, 'Close':63},
              'day-3':{'High': 71, 'Low':65, 'Close':67},
              'day-4':{'High': 70, 'Low':62, 'Close':65},
              'day-5':{'High': 73, 'Low':65, 'Close':70},
              'day-6':{'High': 75, 'Low':69, 'Close':73}
              }

for i in [1,3]:
  print(stock_dict['day-'+i]['Low'])

Solution

The counter i takes integer values, so it cannot be directly concatenated with ‘day-’. To resolve this issue, use 'day-' + str(i) instead.

Question-5

grades = {'Tim':90, 'Amy':95, 'Jack':85, ['Bob', 'Mia']:80}
grades

Solution

The list [‘Bob’, ‘Mia’] cannot be used as a dictionary key because it is mutable.

Question-6

dict(('Tim', 'Jack', 'Mia'))

Solution

The dict() function expects key-value pairs, typically provided as a sequence of 2-element tuples.

Question-7

my_dict = {'A':70, 'B':90, 'C':75, 'D':80}
print(my_dict['E'])

Solution

‘E’ is not a key in my_dict.

Question-8

grades = {'Tim':90, 'Amy':95, 'Jack':85, ('A', 'B'):80}
print(grades['A'])

Solution

‘A’ is not a key in grades dictionary. The tuple (‘A’, ‘B’) is a key.