Intro to Python for Computer Science and Data Science: Learning to Program with AI, Big Data and The Cloud

5.4 Unpacking Sequences

The previous chapter introduced tuple unpacking. You can unpack any sequence’s elements by assigning the sequence to a comma-separated list of variables. A ValueError occurs if the number of variables to the left of the assignment symbol is not identical to the number of elements in the sequence on the right:

In [1]: student_tuple = ('Amanda', [98, 85, 87])

In [2]: first_name, grades = student_tuple

In [3]: first_name
Out[3]: 'Amanda'

In [4]: grades
Out[4]: [98, 85, 87]

The following code unpacks a string, a list and a sequence produced by range:

In [5]: first, second = 'hi'

In [6]: print(f'{first} {second}')
h i

In [7]: number1, number2, number3 = [2, 3, 5]

In [8]: print(f'{number1} {number2} {number3}')
2 3 5

In [9]: ...