Tuples in Python are values separated by commas. Enclosing parentheses for inputting tuples are optional, so the two assignments
a = 1, 2, 3 # a is the tuple (1, 2, 3)
and
a = (1, 2, 3) # a is the tuple (1, 2, 3)
are equivalent. The assignment a = 1, 2, 3 is also called packing because it packs values together in a tuple.
Note that a one-value tuple is also a tuple. To tell Python that a variable is a tuple and not a single value you can use a trailing comma
