Output: Gold: Alice, Silver: Jack, Bronze: Charlie
You can verify this by printing the values: print(f"x: ") Here 1 is assigned to x, 2 to y, 3 to z, and the rest of the values into rest. Let’s unpack the three first coordinate values into separate variables x, y, and z, and then store the rest of the values into a list: coords = 1, 2, 3, 4, 5, 6 This is the only way you do not need to have an equal amount of items on both sides of the expression.įor example, let’s say you have a tuple of 3 coordinate values and 3 additional values that represent something else. However, you can use a wildcard * to catch an arbitrary number of elements from a tuple. This way of unpacking a list is useful in passing list. In the previous section, you learned the left-hand side and the right-hand side of the tuple unpacking expression must have an equal number of items. Sequence unpacking requires that there are as many variables on the left side of the equals sign as there are elements in the sequence. Use the operator before the list object to unpack or spread its elements. Unpack Any Number of Elements with * Operator In the tuple, there are 5 values in total, whereas we only declare two variables to store them all. Here the error says there are too many values to unpack. Output: ValueError: too many values to unpack (expected 2) Output: ValueError: not enough values to unpack (expected 6, got 3)Īs you can see, the unpacking failed because there are not enough values in the tuple to be assigned to 6 variables.Īlso, if the number of new variables is less than the number of elements in the tuple, unpacking fails.įor example, let’s try to pick two values from a tuple of five: coords = 1, 2, 3, 4, 5 Let’s see what happens when the number of variables exceeds the number of elements in the tuple: coords = 1, 2, 3 Make sure you always have the same number of elements on each side of the assignment operator when unpacking a tuple. The Number of Variables Must Equal to the Number of Elements This assigns the value 1 to x, 2 to y, and 3 to z. To make this work, the number of variables must match the number of items in the tuple.įor example, let’s pick all the 3D coordinate values from a tuple into separate variables x, y, and z: coords = 1, 2, 3 To do this, declare a comma-separated group of variable names and assign it to the tuple. In Python, tuples are immutable and ordered data structures. If you need to pick all the values from a tuple into variables, use tuple unpacking. Packing, Unpacking & Extended Unpacking of Tuple in Python. Here is the syntax for accessing elements from a tuple: tuple_valuesįor example, let’s get the first coordinate of the tuple that represents a 3D point: coords = 1, 2, 3 Use the square bracket accessing operator with the index to get the specific element.Specify the index of the element you want to access.In Python, you can access tuples with a similar syntax you would access an element from a list: Tuple unpacking means pulling values apart from the tuple into separate variables.īefore jumping into details about tuple unpacking, let’s take a look at accessing tuple values in the first place.
PYTHON UNPACKING FREE
To learn more about tuples in Python, feel free to check this article. It is worthwhile to notice right from the get-go that a tuple does not necessarily need parenthesis.įor example, you can create the same tuple as above with: nums = 1, 2, 3 You can even pass a part of the tuple, which seems like what you're trying to do here: t (2010, 10, 2, 11, 4, 0, 2, 41, 0) dt datetime.datetime (t 0:7) This is called unpacking a tuple, and can be used for other iterables (such as lists) too. This means you cannot change the tuple in any way after it has been created.įor example, here is a tuple of three integers: nums = (1, 2, 3) 156 Generally, you can use the func (tuple) syntax. 00:30 The single asterisk operator ( ) can be used on any iterable that Python provides, while the double asterisk operator ( ) can only be used on dictionaries. The main difference between a tuple and a list in Python is that a tuple is immutable, whereas a list is mutable. In short, the unpacking operators are operators that unpack the values from iterable objects in Python. Similar to a list, a tuple can store elements of different kinds. In Python, a tuple is one of the basic built-in types.
PYTHON UNPACKING HOW TO
In this guide, you learn about Python tuples, tuple unpacking, and how to use tuple unpacking with other types.
Unpacking is more commonly known as multiple assignment, as it reminds of assigning multiple variables on the same line. You can unpack a list or a string with the same syntax. In Python, unpacking is not limited to tuples only. Python tuple unpacking means pulling values apart from a tuple.
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