141. What is the output of print(len({'a':1, 'b':2}))?
- a) 2
- b) 4
- c) {'a':1, 'b':2}
- d) Error
Answer: A -
len() returns the number of key-value pairs in a dictionary.
142. Which method returns a set of dictionary keys?
- a) keys()
- b) get_keys()
- c) items()
- d) values()
Answer: A -
my_dict.keys() returns a view of all keys.
143. What does print({'a', 'b'} - {'b', 'c'}) output?
- a) {'a'}
- b) {'c'}
- c) {'a', 'c'}
- d) set()
Answer: A - The - operator performs set difference (elements in first set but not in second).
144. Which method returns a default value if a key doesn't exist?
- a) get()
- b) setdefault()
- c) default()
- d) find()
Answer: A -
my_dict.get(key, default) returns default if key is missing.
145. What is the output of print({'a':1} == {'a':1.0})?
- a) True
- b) False
- c) None
- d) Error
Answer: A - Dictionary comparison considers 1 and 1.0 as equal values.
146. Which method removes and returns an arbitrary key-value pair?
- a) popitem()
- b) pop()
- c) remove()
- d) discard()
Answer: A -
my_dict.popitem() removes and returns a random item (Python 3.7+ returns last inserted).
147. What is the output of print(len(set('hello')))?
- a) 4
- b) 5
- c) 1
- d) Error
Answer: A - Sets remove duplicates, so 'hello' becomes {'h','e','l','o'} (length 4).
148. Which operator performs set intersection?
- a) &
- b) |
- c) -
- d) ^
Answer: A - The & operator returns elements common to both sets.
149. What does print({'a':1}.update({'b':2})) output?
- a) None
- b) {'a':1, 'b':2}
- c) {'b':2}
- d) Error
Answer: A -
update() modifies the dictionary in-place and returns None.
150. Which method creates a dictionary from two sequences?
- a) dict(zip(keys, values))
- b) dict.fromkeys(keys, values)
- c) dict.combine(keys, values)
- d) dict.map(keys, values)
Answer: A -
dict(zip(['a','b'], [1,2])) creates {'a':1, 'b':2}.
151. What is the output of print({'a', 'b'} | {'b', 'c'})?
- a) {'a', 'b', 'c'}
- b) {'b'}
- c) {'a', 'c'}
- d) set()
Answer: A - The | operator performs set union (all unique elements from both sets).
152. Which method returns a new dictionary with default values?
- a) fromkeys()
- b) setdefault()
- c) defaults()
- d) newdict()
Answer: A -
dict.fromkeys(['a','b'], 0) creates {'a':0, 'b':0}.
153. What is the output of print('a' in {'a':1})?
- a) True
- b) False
- c) 1
- d) Error
Answer: A - The
in operator checks for key existence in dictionaries.
154. Which method removes a key and returns its value?
- a) pop()
- b) remove()
- c) delete()
- d) discard()
Answer: A -
my_dict.pop('a') removes 'a' and returns its value.
155. What does print({'a':1}.copy()) output?
- a) {'a':1}
- b) ['a',1]
- c) ('a',1)
- d) Error
Answer: A -
copy() creates a shallow copy of the dictionary.
156. Which operator performs symmetric difference (elements in either set but not both)?
- a) ^
- b) &
- c) |
- d) -
Answer: A - The ^ operator returns elements in either set but not in both.
157. What is the output of print(bool(set()))?
- a) False
- b) True
- c) None
- d) Error
Answer: A - Empty sets are falsy in Python.
158. Which method adds an element to a set?
- a) add()
- b) append()
- c) insert()
- d) push()
Answer: A -
my_set.add(x) adds x to the set.
159. What does print({'a':1}.get('b', 2)) output?
- a) 2
- b) None
- c) 1
- d) Error
Answer: A - Returns the default value (2) when key 'b' doesn't exist.
160. Which method removes an element from a set without raising an error if missing?
- a) discard()
- b) remove()
- c) pop()
- d) delete()
Answer: A -
my_set.discard(x) removes x if present (no error if not found).