◐ Shell
clean mode source ↗

gh-139871: Fix 3.15 bytearray.take_bytes example by cmaloney · Pull Request #149520 · python/cpython

Currently:
```python
buffer = bytearray(b'abc\ndef')
n = buffer.find(b'\n')
data = bytes(buffer[:n + 1])
del buffer[:n + 1]
assert data == b'abc'
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
    assert data == b'abc'
           ^^^^^^^^^^^^^^
AssertionError
```

Adding in the `\n` makes the two match:

```python
buffer = bytearray(b'abc\ndef')
n = buffer.find(b'\n')
data = bytes(buffer[:n + 1])
del buffer[:n + 1]
assert data == b'abc\n'
assert buffer == bytearray(b'def')

buffer = bytearray(b'abc\ndef')
n = buffer.find(b'\n')
data = buffer.take_bytes(n + 1)
assert data == b'abc\n'
assert buffer == bytearray(b'def')
```

@cmaloney added the 3.15

pre-release feature fixes, bugs and security fixes

label

May 7, 2026

JelleZijlstra

JelleZijlstra pushed a commit that referenced this pull request

May 9, 2026
…149622)

gh-139871: Fix 3.15 bytearray.take_bytes example (GH-149520)

Currently:
```python
buffer = bytearray(b'abc\ndef')
n = buffer.find(b'\n')
data = bytes(buffer[:n + 1])
del buffer[:n + 1]
assert data == b'abc'
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
    assert data == b'abc'
           ^^^^^^^^^^^^^^
AssertionError
```

Adding in the `\n` makes the two match:

```python
buffer = bytearray(b'abc\ndef')
n = buffer.find(b'\n')
data = bytes(buffer[:n + 1])
del buffer[:n + 1]
assert data == b'abc\n'
assert buffer == bytearray(b'def')

buffer = bytearray(b'abc\ndef')
n = buffer.find(b'\n')
data = buffer.take_bytes(n + 1)
assert data == b'abc\n'
assert buffer == bytearray(b'def')
```
(cherry picked from commit cc5cf14)

Co-authored-by: Cody Maloney <cmaloney@users.noreply.github.com>

@cmaloney cmaloney deleted the cmaloney/take_bytes_broken_example branch

May 9, 2026 22:15