Proper way to use dynamic keys for TypedDict
Open
Nobody has claimed this yet.
false-positive
feature
priority-2-low
topic-literal-types
topic-typed-dict
- Dominant language
- Python
- Stars
- 20.6k
- Forks
- 3.3k
- PR merge metrics
- PR metrics pending
Description
Is there a way to use dynamic keys for a TypedDict which is properly typed? I have code like this:
if name in ['visible', 'value', 'locked']:
obj[name] = self.use_var_expr(scope, value)
Where obj is a TypedDict that has the same type for the keys 'visible', 'value', 'locked'.
I know that name is not a literal string, but it's been verified to belong to a set of literal strings that belong to the TypedDict.
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Reproduce the TypedDict assignment shown in the issue, focusing on the membership check against ['visible', 'value', 'locked']. Determine whether mypy can type-check this pattern; done means either the pattern is accepted with correct types or the limitation and supported alternative are documented.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- python
- Domain
- devtools
- Issue type
- Feature
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Activity status
- Stale
- Clarity
- Needs clarification
- Newbie friendliness
- 30/100