Which following is a tuple? A. [6, 5, 4] B. (2) C. 7 D. {3, 2, 1}
The correct answer and explanation is:
The correct answer is B. (2).
A tuple in Python is an immutable ordered collection of elements. Tuples are typically enclosed in parentheses (), and they can store multiple items, just like lists. However, there is a significant difference between a list and a tuple: tuples are immutable, meaning once created, their elements cannot be changed, added, or removed.
To better understand why B is a tuple, consider the following:
- A. [6, 5, 4]: This is a list because it is enclosed in square brackets
[]. Lists are mutable, meaning you can add, remove, or change the elements of a list after its creation. - B. (2): This appears to be a tuple, but in reality, this is not a tuple. In Python, a single element in parentheses does not automatically create a tuple. To define a tuple with a single element, you need to have a trailing comma, like this:
(2,). Without the comma, Python treats it as just a regular expression for grouping. - C. 7: This is simply an integer, not a tuple. A tuple can only be created using multiple elements or a single element enclosed in parentheses with a comma.
- D. {3, 2, 1}: This is a set, not a tuple. Sets are unordered collections of unique elements enclosed in curly braces
{}.
Therefore, a tuple is best represented by an ordered collection of elements in parentheses. If you want to define a tuple with a single element, always remember to include a trailing comma (e.g., (2,)). This distinction is important for avoiding confusion with simple expressions like (2) that do not create a tuple.