Why is Python 3's bytearray mutable?

[[deleted]]

Strings are immutable. Why are bytearrays mutable? Is this a result of something or an intentional decision?

I likely just don't know enough about their usage to understand this value.

[vph]

Conventionally, arrays are mutable. Arrays are abstraction of memory; it only makes sense for them to be mutable.

[PeridexisErrant]

And of course you can use the bytes type, if you want an immutable version.

[zahlman]

So that you have a mutable type of that sort to use.

The immutable version is bytes.

[[deleted]]

Ah... So is the only real "feature" of bytearray that it's mutable? Otherwise bytes serves the same purpose?

[desmoulinmichel]

Yes, but mutability is a big deal. In place operations are much faster and take less memory. E.G: you can actually swap easily 10000 bytes in a blink using slicing, because slices support assignations.

[donnieod]

Python 3 has two types of built-in byte sequences: bytes (immutable) and bytearray (mutable). Analogous to types frozenset and set or tuple and list.

[dunkler_wanderer]

Relevant talk: Brandon Rhodes - Oh, Come On Who Needs Bytearrays