Python Dictionaries

1. Which of the following will result in an error for a given valid dictionary D?

• D+3  

• D*3  

• D.update({3:"3"})

• D.update("3":3)

Which of the following are true of Python dictionaries:

• Dictionaries can be nested to any depth.

• Dictionaries are accessed by key.

• All the keys in a dictionary must be of the same type.

• Dictionaries are mutable.

• A dictionary can contain any object type except another dictionary.

You have the following dictionary definition:

d = {'foo': 100, 'bar': 200, 'baz': 300}

What method call will delete the entry whose value is 200?

• delete d('bar')

• d.pop("bar")

• d.remove("bar")

• None of the above

What would be the output of the following code snippet?

a_dict = {'color': 'blue', 'fruit': 'apple', 'pet': 'dog'}

for key in a_dict:

print(key)

• 'blue'

  'apple'

  'dog'

• color

  fruit

  pet

• blue

  apple

  dog

• 'color'

  'fruit'

  'pet'

What would be the output of the following code snippet?

a_dict = {'color': 'blue', 'fruit': 'apple', 'pet': 'dog'}

d_items = a_dict.items()

print(d_items)

• ('color', 'blue'), ('fruit', 'apple'), ('pet', 'dog')

• dict_items([('color'), ('fruit'), ('pet')])

• [('color', 'blue'), ('fruit', 'apple'), ('pet', 'dog')]

• dict_items([('color', 'blue'), ('fruit', 'apple'), ('pet', 'dog')])

Which of the following create an empty dictionary (D)?

• D = dict()

• D = ()

• D = []

• D = {}

Which symbol surrounds a dictionary?

• {
• (
• [
• :

________________method will returns number of key-value pairs in the given dictionary.

• len( )

• pop( )

• del( )

• keys( )

• values( )

Which of the following will give error?

Suppose dict1={"a":1,"b":2,"c":3}

• print(len(dict1))

• print(dict1.get("b"))

• dict1["a"]=5

• None of these.

A Python dictionary stores ...

• value - key pairs

• key - value pairs