readline0 1.7

Read lines of data with an arbitrary delimiter, like a null, newline or even an x.

It passes pylint, passes pycodestyle, passes pydocstyle, is thoroughly unit tested, and runs on CPython 2.7, CPython 3.x, Pypy 7.3.1, and Pypy3 7.3.1.

It gains a lot of speed by eschewing single-character reads.

Usage looks like:

import readline0
file_ = open('/etc/shells', 'r')
for line in readline0.readline0(file_=file_, separator=b'\n'):
...     print(line)
...
b'# /etc/shells: valid login shells'
b'/bin/sh'
b'/bin/dash'
b'/bin/bash'
b'/bin/rbash'

Of course separator need not be a newline; it defaults to a null byte. Also file_ defaults to sys.stdin. And there’s a blocksize argument as well, which defaults to 64K.