How to Create a Tuple in Python

The best way to understand why you should get in the habit of using parentheses when creating tuples is to look at some Python code:

def show_type(obj):
    print(type(obj))

#tuple created w/o parentheses (works but bad practice)
MAGENTA = 255, 0, 255
show_type(MAGENTA)

#When passing a tuple to a function, you need parentheses:
show_type( (255, 0, 255) )

#Passing the tuple w/o parentheses to a function will error
show_type( 255, 0, 255 )

The above code will render the following:

1. On line 5, the MAGENTA tuple is created without using parentheses.
2. By passing MAGENTA to the show_type() function, we see that MAGENTA is indeed a tuple.
3. On line 9, the tuple (255, 0, 255) (constructed with parentheses) is passed to the show_type() function. This works fine.
4. On line 12, the tuple (well, not really) 255, 0, 255 (constructed without parentheses) is passed to the show_type() function. In this case, Python passes the values to the show_type() function as three separate arguments. As the function only expects one argument, this results in an error: TypeError: show_type() takes 1 positional argument but 3 were given.

Creating a Single-element Tuple

To create an empty tuple, use an empty set of parentheses:

veggies_my_son_likes = ()

To create a single-element tuple, follow the element with a comma, like this:

pitchers_with_500_wins = ('Cy Young',)

If you do not include the comma, you just get a string as illustrated below:

So, in a nutshell, tuples are created with commas, but you should wrap them in parentheses.