What types of objects can be part of a set in Python?

In Python, a set can only contain hashable objects. This means objects must be immutable and have a hash() method.

Typical objects that can be included in a set:

• Numbers (int, float, complex)
• Strings (str)
• Tuples (tuple), if all elements of the tuple are also hashable
• Boolean values (bool)

Objects that cannot be elements of a set:

• Lists (list)
• Dictionaries (dict)
• Sets (set)

Example:

s = {1, "hello", (2, 3)}  # correct
s.add([4,5])  # will raise a TypeError