Import module doesn't updated

@terryjreedy

BPO	41770
Nosy	@terryjreedy, @stevendaprano, @cheny0y0

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

Show more details

GitHub fields:

assignee = None
closed_at = <Date 2020-09-18.23:09:22.379>
created_at = <Date 2020-09-12.03:00:14.826>
labels = ['interpreter-core', 'invalid', 'type-bug', '3.8']
title = "Import  module doesn't updated"
updated_at = <Date 2020-09-18.23:09:22.378>
user = 'https://github.com/cheny0y0'

bugs.python.org fields:

activity = <Date 2020-09-18.23:09:22.378>
actor = 'terry.reedy'
assignee = 'none'
closed = True
closed_date = <Date 2020-09-18.23:09:22.379>
closer = 'terry.reedy'
components = ['Interpreter Core']
creation = <Date 2020-09-12.03:00:14.826>
creator = 'prasechen'
dependencies = []
files = []
hgrepos = []
issue_num = 41770
keywords = []
message_count = 5.0
messages = ['376766', '376767', '376770', '376818', '377142']
nosy_count = 3.0
nosy_names = ['terry.reedy', 'steven.daprano', 'prasechen']
pr_nums = []
priority = 'normal'
resolution = 'not a bug'
stage = 'resolved'
status = 'closed'
superseder = None
type = 'behavior'
url = 'https://bugs.python.org/issue41770'
versions = ['Python 3.8']

# I create a module:
# \sys.path\xxx.py
a = 9
# And:
>>> import xxx
>>> xxx.a
9
# I delete this imported module and modified this module:
del xxx
# \sys.path\xxx.py
a = 9
b = 8
# And re-import:
>>> import xxx
>>> xxx.b
# But:
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: type object 'xxx' has no attribute 'b'

Hi, you just need to call del sys.modules['xxx'] and have a look at https://docs.python.org/3.7/library/importlib.html#importlib.invalidate_caches

before importing again

This is not a bug, it is working as designed. Importing takes the module from the cache. You can either delete the module from the cache:

del sys.modules['modulename']
import modulename  # reloads from the module file

or possibly simpler, use reload:

    importlib.reload(modulename)

--REOPEN--
>>> # I try:
>>> import xxx
>>> del sys.modules['xxx']
>>> # But:
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
    del sys.modules['xxx']
NameError: name 'sys' is not found
>>> # I try to import sys.
>>> import sys
>>> del sys.modules['xxx']
>>> import xxx
>>> xxx.b
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: module 'xxx' has no attribute 'b'

I carefully redid your test, corrected, 3 times, and it works as expected.
Win 10, 3.9.0rc2.

>>> import a.tem3 as t
>>> t.b
Traceback (most recent call last):
  File "<pyshell#23>", line 1, in <module>
    t.b
AttributeError: module 'a.tem3' has no attribute 'b'

# Add 'b = 2' to a/tem3.py and save.

>>> import sys
>>> del sys.modules['a.tem3']
>>> import a.tem3 as t
>>> t.b
2

Without seeing exactly what you did and when, I can only guess that you imported a version of xxx without the 'b' binding. I once added it but *forgot to save* before re-importing. Note that dictionary deletion and importing are well tested operations, so that bugs in normal imports are very unlikely. If you really get a failure, there must be some relevant details that you have omitted, like importing from a remote system that is locally cached, with the local cache unchanged by editing the remote original. Or having an OS bug such that saving a file does not update the 'last changed' time.

If you disagree with a closing, please request re-opening and give us a chance to reproduce and discuss first rather than doing so yourself.

Navigation Menu

Repository navigation

Import module doesn't updated #85936

2 remaining items

Metadata

Assignees

Labels

Projects

Milestone

Relationships

Development

Import module doesn't updated #85936

Description

Activity

cheny0y0 commented on Sep 12, 2020

pmp-p commented on Sep 12, 2020

stevendaprano commented on Sep 12, 2020

2 remaining items

cheny0y0 commented on Sep 13, 2020

terryjreedy commented on Sep 18, 2020

Metadata

Metadata

Assignees

Labels

Projects

Milestone

Relationships

Development

Issue actions