Create or declare a tuple in Python

A Python tuple is the data type containing multiple elements like a list or dictionary. All elements are separated with a comma and enclosed in round brackets. Tuples are declared as follows.

a = (1, 2, 3)
b = ('pen', 'book')

print(a)  # (1, 2, 3)
print(b)  # ('pen', 'book')

Both variables are tuples. Empty tuple is created like this.

a = ()

print(a)  # ()
print(type(a))  # <class 'tuple'>

You can write a trailing comma declaring a tuple. Basically the last comma doesn't mean there is another element.

a = (1, 2, 3,)

print(a)  # (1, 2, 3)

The advantage of trailing commas can be found in the following code.

a = (
    1,
    2,
    3,
)

print(a)  # (1, 2, 3)

In Python programming, a value can be represented so long that it's better to align elements vertically than horizontally in a tuple or list. The trailing comma fits in the alignment meaning clearly the value is an element of a tuple.

Even if you like to use the trailing comma, it's good that you and your team are consistent with usage of it.