zoneinfo: ZoneInfo raises IsADirectoryError instead of ZoneInfoNotFoundError

[bijij]

BPO	41530
Nosy	@vstinner, @pganssle, @bijij
PRs	bpo-41530: Handle unhandled IsADirectoryError and PermissionError in zoneinfo.ZoneInfo #21839

^{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 = None
closed_at = None
created_at = <Date 2020-08-12.11:42:16.788>
labels = ['type-bug', 'library', '3.9', '3.10']
title = 'zoneinfo: ZoneInfo raises IsADirectoryError instead of ZoneInfoNotFoundError'
updated_at = <Date 2020-08-12.14:46:45.318>
user = 'https://github.com/bijij'

bugs.python.org fields:

activity = <Date 2020-08-12.14:46:45.318>
actor = 'josh.ja.butt'
assignee = 'none'
closed = False
closed_date = None
closer = None
components = ['Library (Lib)']
creation = <Date 2020-08-12.11:42:16.788>
creator = 'josh.ja.butt'
dependencies = []
files = []
hgrepos = []
issue_num = 41530
keywords = ['patch']
message_count = 10.0
messages = ['375225', '375226', '375228', '375233', '375234', '375235', '375238', '375239', '375240', '375251']
nosy_count = 4.0
nosy_names = ['vstinner', 'python-dev', 'p-ganssle', 'josh.ja.butt']
pr_nums = ['21839']
priority = 'normal'
resolution = None
stage = 'patch review'
status = 'open'
superseder = None
type = 'behavior'
url = 'https://bugs.python.org/issue41530'
versions = ['Python 3.9', 'Python 3.10']

Linked PRs

• gh-85702: Catch IsADirectoryError in zoneinfo #131333

[bijij]

Attempting to parse specific keys in zoneinfo.ZoneInfo with tzdata installed will raise unhandled exceptions

e.g. on windows

>>> import zoneinfo
>>> zoneinfo.ZoneInfo('Pacific')
PermissionError: [Errno 13] Permission denied: 'C:\\Program Files\\Python39\\lib\\site-packages\\tzdata\\zoneinfo\\Pacific'

>>> import zoneinfo
>>> zoneinfo.ZoneInfo('__init__.py')
ValueError: Invalid TZif file: magic not found

This happens when non TZif files or directories in the tzdata.zoneinfo module are used as keys.

[vstinner]

Hi. It seems like you are running Windows.

About the permission error, how did you install tzdata? Did you install it as an admin user and do you run Python as a different user?

[bijij]

tzdata was installed as an admin user, however this behaviour was
reproducible on a linux installation where for the ZoneInfo.('Pacific')
instance an IsADirectoryError would instead be raised.

On Wed, Aug 12, 2020 at 9:50 PM STINNER Victor <report@bugs.python.org>
wrote:

STINNER Victor <vstinner@python.org> added the comment:

Hi. It seems like you are running Windows.

About the permission error, how did you install tzdata? Did you install it
as an admin user and do you run Python as a different user?

----------
nosy: +vstinner

---

Python tracker <report@bugs.python.org>
<https://bugs.python.org/issue41530\>

---

[vstinner]

Oh right, 'Pacific' is a directory, not a valid zone, and so ZoneInfoNotFoundError should be raised. I see.

Example:

$ ./python -m venv env
$ env/bin/python -m pip install tzdata
$ env/bin/python 

# ZoneInfoNotFoundError expected, get IsADirectoryError
>>> import zoneinfo; zoneinfo.ZoneInfo('Pacific')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/vstinner/python/master/Lib/zoneinfo/_common.py", line 12, in load_tzdata
    return importlib.resources.open_binary(package_name, resource_name)
  File "/home/vstinner/python/master/Lib/importlib/resources.py", line 40, in open_binary
    return reader.open_resource(resource)
  File "/home/vstinner/python/master/Lib/importlib/abc.py", line 419, in open_resource
    return self.files().joinpath(resource).open('rb')
  File "/home/vstinner/python/master/Lib/pathlib.py", line 1238, in open
    return io.open(self, mode, buffering, encoding, errors, newline,
IsADirectoryError: [Errno 21] Is a directory: '/home/vstinner/python/master/env/lib/python3.10/site-packages/tzdata/zoneinfo/Pacific'

# valid zone
>>> import zoneinfo; zoneinfo.ZoneInfo('Pacific/Noumea')
zoneinfo.ZoneInfo(key='Pacific/Noumea')

# raise ZoneInfoNotFoundError as expected (from FileNotFoundError)
>>> import zoneinfo; zoneinfo.ZoneInfo('xxx')
Traceback (most recent call last):
  File "/home/vstinner/python/master/Lib/zoneinfo/_common.py", line 12, in load_tzdata
    return importlib.resources.open_binary(package_name, resource_name)
  File "/home/vstinner/python/master/Lib/importlib/resources.py", line 40, in open_binary
    return reader.open_resource(resource)
  File "/home/vstinner/python/master/Lib/importlib/abc.py", line 419, in open_resource
    return self.files().joinpath(resource).open('rb')
  File "/home/vstinner/python/master/Lib/pathlib.py", line 1238, in open
    return io.open(self, mode, buffering, encoding, errors, newline,
  File "/home/vstinner/python/master/Lib/pathlib.py", line 1106, in _opener
    return self._accessor.open(self, flags, mode)
FileNotFoundError: [Errno 2] No such file or directory: '/home/vstinner/python/master/env/lib/python3.10/site-packages/tzdata/zoneinfo/xxx'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/vstinner/python/master/Lib/zoneinfo/_common.py", line 24, in load_tzdata
    raise ZoneInfoNotFoundError(f"No time zone found with key {key}")
zoneinfo._common.ZoneInfoNotFoundError: 'No time zone found with key xxx'

[vstinner]

On Linux, converting IsADirectoryError to ZoneInfoNotFoundError is easy.

But on Windows, I don't think that converting any PermissionError into a ZoneInfoNotFoundError is a good idea. Maybe if PermissionError happens, we should check if the path is a directory.

Pseudo-code:

try:
<open and read file>
except OSError as exc:
if os.path.isdir(zone_path):
raise ZoneInfoNotFoundError
else:
raise