Optimize BytesIO to do less reallocations when written, similarly to StringIO #59586

assignee = 'https://github.com/serhiy-storchaka'
closed_at = None
created_at = <Date 2012-07-17.12:12:45.969>
labels = ['library', 'performance']
title = 'Optimize BytesIO to do  less reallocations when written, similarly to StringIO'
updated_at = <Date 2019-03-15.22:56:18.774>
user = 'https://bugs.python.org/elibendersky'

activity = <Date 2019-03-15.22:56:18.774>
actor = 'BreamoreBoy'
assignee = 'serhiy.storchaka'
closed = False
closed_date = None
closer = None
components = ['Library (Lib)']
creation = <Date 2012-07-17.12:12:45.969>
creator = 'eli.bendersky'
dependencies = []
files = ['26461', '32536', '36180', '36369', '36371', '37939']
hgrepos = []
issue_num = 15381
keywords = ['patch']
message_count = 47.0
messages = ['165715', '165716', '165718', '165748', '165760', '165780', '165795', '165883', '165884', '165901', '165935', '165937', '165976', '165977', '165978', '165979', '165980', '165981', '165995', '166005', '166007', '166008', '166043', '171205', '202374', '203034', '203045', '224409', '225272', '225274', '225276', '225295', '225298', '225306', '225311', '225316', '225317', '225318', '234885', '235103', '235326', '235339', '235340', '235353', '236003', '236007', '236011']
nosy_count = 17.0
nosy_names = ['ncoghlan', 'pitrou', 'scoder', 'vstinner', 'benjamin.peterson', 'stutzbach', 'Arfrever', 'eli.bendersky', 'meador.inge', 'tshepang', 'python-dev', 'jcon', 'berker.peksag', 'hynek', 'dw', 'serhiy.storchaka', 'kmike']
pr_nums = []
priority = 'normal'
resolution = None
stage = 'patch review'
status = 'open'
superseder = None
type = 'performance'
url = 'https://bugs.python.org/issue15381'
versions = ['Python 3.5']