How to Ignore Values When Unpacking in Python

In Python, you can ignore values when unpacking by assigning them to the underscore _ variable, which is a common convention for unused values. For example, a, _, c = (1, 2, 3) assigns 1 to a, ignores 2, and assigns 3 to c.

Syntax

When unpacking a sequence, use _ as a placeholder for values you want to ignore. This tells Python you don't need that value.

• a, _, c = sequence: assigns first and third values, ignores the second.
• You can use multiple underscores to ignore multiple values.

python

a, _, c = (1, 2, 3)
print(a)
print(c)

Output

1
3

Example

This example shows unpacking a tuple with three values but ignoring the middle one using _. Only the first and last values are kept.

python

data = (10, 20, 30)
a, _, c = data
print(f"First: {a}")
print(f"Ignored middle value")
print(f"Last: {c}")

Output

First: 10
Ignored middle value
Last: 30

Common Pitfalls

Some common mistakes when ignoring values:

• Using a named variable instead of _ will keep the value, which may confuse readers.
• Using _ multiple times in the same scope can overwrite previous ignored values.
• For ignoring multiple values, use multiple underscores like _, _, c = (1, 2, 3).

python

x, y, z = (1, 2, 3)  # Wrong if you want to ignore y
print(x, z)

_, _, z = (1, 2, 3)  # Correct to ignore first two
print(z)

Output

1 3
3

Quick Reference

Pattern	Description
a, _, c = sequence	Ignore the middle value
_, b, _ = sequence	Ignore first and last values, keep middle
_, _, c = sequence	Ignore first two values, keep last
a, *_, c = sequence	Ignore all middle values, keep first and last

Key Takeaways

Use underscore (_) to ignore unwanted values when unpacking sequences.

Multiple underscores can ignore multiple values in order.

Avoid using named variables if you want to clearly ignore values.

Using * with _ can ignore multiple middle values in unpacking.

Ignoring values improves code readability by showing intent clearly.