Fix circular import of config_validation and template

[palfrey]

Proposed change

Correct circular imports of config_validation. Without this fix the following occurs:

>>> from homeassistant.components.http import HomeAssistantView
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/palfrey/src/home-assistant-core/homeassistant/components/http/__init__.py", line 20, in <module>
    from homeassistant.helpers import storage
  File "/home/palfrey/src/home-assistant-core/homeassistant/helpers/storage.py", line 10, in <module>
    from homeassistant.helpers.event import async_call_later
  File "/home/palfrey/src/home-assistant-core/homeassistant/helpers/event.py", line 47, in <module>
    from homeassistant.helpers.template import RenderInfo, Template, result_as_boolean
  File "/home/palfrey/src/home-assistant-core/homeassistant/helpers/template.py", line 35, in <module>
    from homeassistant.helpers import config_validation as cv, location as loc_helper
  File "/home/palfrey/src/home-assistant-core/homeassistant/helpers/config_validation.py", line 519, in <module>
    def template(value: Optional[Any]) -> template_helper.Template:
AttributeError: partially initialized module 'homeassistant.helpers.template' has no attribute 'Template' (most likely due to a circular import)

So you fix the config_validation.py error, and then get the following in location.py

>>> from homeassistant.components.http import HomeAssistantView
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/palfrey/src/home-assistant-core/homeassistant/components/http/__init__.py", line 20, in <module>
    from homeassistant.helpers import storage
  File "/home/palfrey/src/home-assistant-core/homeassistant/helpers/storage.py", line 10, in <module>
    from homeassistant.helpers.event import async_call_later
  File "/home/palfrey/src/home-assistant-core/homeassistant/helpers/event.py", line 47, in <module>
    from homeassistant.helpers.template import RenderInfo, Template, result_as_boolean
  File "/home/palfrey/src/home-assistant-core/homeassistant/helpers/template.py", line 35, in <module>
    from homeassistant.helpers import location as loc_helper
  File "/home/palfrey/src/home-assistant-core/homeassistant/helpers/location.py", line 10, in <module>
    import homeassistant.helpers.config_validation as cv
  File "/home/palfrey/src/home-assistant-core/homeassistant/helpers/config_validation.py", line 519, in <module>
    def template(value: Optional[Any]) -> template_helper.Template:
AttributeError: partially initialized module 'homeassistant.helpers.template' has no attribute 'Template' (most likely due to a circular import)

After this fix:

>>> from homeassistant.components.http import HomeAssistantView
>>>

Type of change

• Dependency upgrade
• Bugfix (non-breaking change which fixes an issue)
• New integration (thank you!)
• New feature (which adds functionality to an existing integration)
• Breaking change (fix/feature causing existing functionality to break)
• Code quality improvements to existing code or addition of tests

Additional information

• This PR fixes or closes issue: fixes #
• This PR is related to issue:
• Link to documentation pull request:

Checklist

• The code change is tested and works locally.
• Local tests pass. Your PR cannot be merged unless tests pass
• There is no commented out code in this PR.
• I have followed the development checklist
• The code has been formatted using Black (black --fast homeassistant tests)
• Tests have been added to verify that the new code works.

If user exposed functionality or configuration variables are added/changed:

• Documentation added/updated for www.home-assistant.io

If the code communicates with devices, web services, or third-party tools:

• The manifest file has all fields filled out correctly.
  Updated and included derived files by running: python3 -m script.hassfest.
• New or updated dependencies have been added to requirements_all.txt.
  Updated by running python3 -m script.gen_requirements_all.
• Untested files have been added to .coveragerc.

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[homeassistant]

Hi @palfrey,

It seems you haven't yet signed a CLA. Please do so here.

Once you do that we will be able to review and accept this pull request.

Thanks!

[bdraco]

Verified the circular import exists. That makes testing more difficult.

Would you please fix the merge conflict.

[palfrey]

Would you please fix the merge conflict.

Done

[bdraco]

confirmed its fixed

>>> import homeassistant.helpers.template
>>> 

[bdraco]

Looks like this fixes the HACS CI as well 👍

Traceback (most recent call last):
  File "/hacs/action.py", line 10, in <module>
    from custom_components.hacs.hacsbase.configuration import Configuration
  File "/hacs/custom_components/hacs/__init__.py", line 13, in <module>
    from .operational.setup import (
  File "/hacs/custom_components/hacs/operational/setup.py", line 8, in <module>
    from homeassistant.helpers.event import async_call_later
  File "/usr/lib/python3.8/site-packages/homeassistant/helpers/event.py", line 48, in <module>
    from homeassistant.helpers.template import RenderInfo, Template, result_as_boolean
  File "/usr/lib/python3.8/site-packages/homeassistant/helpers/template.py", line 34, in <module>
    from homeassistant.helpers import config_validation as cv, location as loc_helper
  File "/usr/lib/python3.8/site-packages/homeassistant/helpers/config_validation.py", line 534, in <module>
    def template(value: Optional[Any]) -> template_helper.Template:
AttributeError: partially initialized module 'homeassistant.helpers.template' has no attribute 'Template' (most likely due to a circular import)