Question

which of the following is not a valid key in a dictionary?
string
integer
list
tuple
question 20
what does the following code do?
my_set = {1, 2, 3}
my_set.remove(2)
print(my_set)
adds 2 to the set
removes 2 from the set
prints the entire set
raises an error

Explanation:

• In Python, dictionary keys must be hashable. Strings, integers, and tuples are hashable (tuples with only hashable elements). Lists are not hashable because they are mutable (can be changed), so they cannot be dictionary keys.
• For the set operation, the remove() method in Python sets is used to remove a specific element. Here, my_set.remove(2) removes the element 2 from the set {1, 2, 3}. Then print(my_set) will print the modified set.

Answer:

• First question: List is not a valid key in a dictionary.
• Second question: Removes 2 from the set.