bytes and bytearray constructors replace unexpected exceptions

[serhiy-storchaka]

BPO	34974
Nosy	@abalkin, @methane, @serhiy-storchaka, @miss-islington
PRs	bpo-34974: Do not replace unexpected errors in bytes() and bytearray(). #9852 [3.7] bpo-34974: Do not replace unexpected errors in bytes() and bytearray(). (GH-9852) #9878 [3.6] bpo-34974: Do not replace unexpected errors in bytes() and bytearray(). (GH-9852) #9879 [2.7] bpo-34974: Do not replace unexpected errors in bytearray(). (GH-9852) #9885

^{Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.}

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GitHub fields:

assignee = 'https://github.com/serhiy-storchaka'
closed_at = <Date 2018-10-15.05:46:54.510>
created_at = <Date 2018-10-13.19:18:56.703>
labels = ['interpreter-core', '3.8', 'type-bug', '3.7']
title = 'bytes and bytearray constructors replace unexpected exceptions'
updated_at = <Date 2018-10-15.05:46:54.510>
user = 'https://github.com/serhiy-storchaka'

bugs.python.org fields:

activity = <Date 2018-10-15.05:46:54.510>
actor = 'serhiy.storchaka'
assignee = 'serhiy.storchaka'
closed = True
closed_date = <Date 2018-10-15.05:46:54.510>
closer = 'serhiy.storchaka'
components = ['Interpreter Core']
creation = <Date 2018-10-13.19:18:56.703>
creator = 'serhiy.storchaka'
dependencies = []
files = []
hgrepos = []
issue_num = 34974
keywords = ['patch']
message_count = 5.0
messages = ['327661', '327721', '327722', '327723', '327730']
nosy_count = 4.0
nosy_names = ['belopolsky', 'methane', 'serhiy.storchaka', 'miss-islington']
pr_nums = ['9852', '9878', '9879', '9885']
priority = 'normal'
resolution = 'fixed'
stage = 'resolved'
status = 'closed'
superseder = None
type = 'behavior'
url = 'https://bugs.python.org/issue34974'
versions = ['Python 2.7', 'Python 3.6', 'Python 3.7', 'Python 3.8']

[serhiy-storchaka]

bytes() and bytearray() replace some unexpected exceptions (including MemoryError and KeyboardInterrupt) with TypeError.

1. Exception in __index__.

class X:
    def __index__(self):
        raise MemoryError

bytes(X()) results in:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: cannot convert 'X' object to bytes

bytearray(X()) results in:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: 'X' object is not iterable

This is related to bpo-29159.

2. Exception in __iter__.

class X:
    def __iter__(self):
        raise MemoryError

bytes(X()) results in:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: cannot convert 'X' object to bytes

bytearray(X()) works correctly (raises a MemoryError).

The proper solution is to replace just a TypeError and allow other exceptions to emerge.

[serhiy-storchaka]

New changeset e890421 by Serhiy Storchaka in branch 'master':
bpo-34974: Do not replace unexpected errors in bytes() and bytearray(). (GH-9852)
e890421

[miss-islington]

New changeset 1370832 by Miss Islington (bot) in branch '3.7':
bpo-34974: Do not replace unexpected errors in bytes() and bytearray(). (GH-9852)
1370832

[miss-islington]

New changeset 08ba7eb by Miss Islington (bot) in branch '3.6':
bpo-34974: Do not replace unexpected errors in bytes() and bytearray(). (GH-9852)
08ba7eb

[serhiy-storchaka]

New changeset 43308df by Serhiy Storchaka in branch '2.7':
[2.7] bpo-34974: Do not replace unexpected errors in bytearray(). (GH-9852) (GH-9885)
43308df