ValueError too many values to unpack expected [X] : Solved

valueerror too many values to unpack expected error occurs when we try to assign or return any sequence to a set of placeholder variables and the number of placeholder variables does not match with the length of the sequence. There may be various scenarios where this ValueError can occur but the root cause will always be the same. In this article, we will explore this Python error’s solution with examples.

Valueerror too many values to unpack expected [X] (Replication ) –

Case 1: Issue with Sequence & Iterable object –

Let’s initialize the sequence and then unpack them like below.

seq=[1,2,3]
a,v=seq

valueerror too many values to unpack expected [X]

Here you can see the length of the seq is three however we have used only two placeholders. Since it is not fitting completely the sequence, this is why the interpreter will throw the same ValueError.

Case 2: In case of Function Returns mismatch –

Suppose you have created a function in Python where you are returning some variable but we are assigning the output in some placeholder which has lesser length than the returned output. Here is the replication for the same.

too many values to unpack expected replication with function

Valueerror too many values to unpack expected [X] (Solution) –

We can resolve this error in two ways. Let’s explore them one by one.

Solution 1: Use ‘_’ as a placeholder –

In case you are not very sure about the length of the sequence or iterable object then you can use ‘_’ as a placeholder. It will store all the rest elements of the sequence. Let’s see the implementation for more clarity.

too many values to unpack expected Solution

In the above example, we have created two variables as a placeholder and one ‘_’ for storing the rest of all parameters.

Solution 2: Create an equal Placeholder as per the length of the Sequence –

If we are sure of the length then we Create an equal Placeholder as per the length of the Sequence simply. Like here in the sequence, we have three elements then we should take three placeholders.

Thanks

Data Science Learner Team