[New-bugs-announce] [issue43787] Optimize BZ2File, GzipFile, and LZMAFile __iter__ method.

[Inada Naoki]

New submission from Inada Naoki <songofacandy at gmail.com>:

__iter__ method of BZ2File, GzipFile, and LZMAFile is IOBase.__iter__. It calls `readline()` for each line.

Since `readline()` is defined as Python function, it is slower than C iterator. Adding custom __iter__ method that delegates to underlying buffer __iter__ makes `for line in file` 2x faster.

    def __iter__(self):
        self._check_can_read()
        return self._buffer.__iter__()

---

The original issue is reported here.
https://discuss.python.org/t/non-optimal-bz2-reading-speed/6869
This issue is relating to #43785.

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components: Library (Lib)
messages: 390599
nosy: methane
priority: normal
severity: normal
status: open
title: Optimize BZ2File, GzipFile, and LZMAFile __iter__ method.
type: performance
versions: Python 3.10

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Python tracker <report at bugs.python.org>
<https://bugs.python.org/issue43787>
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