Pandera Schema Hover
See a pandera schema's columns right where you use the DataFrame. No jumping to the definition.
With pandera, a hover over a typed DataFrame only tells you the
schema's name:
(variable) orders: DataFrame[OrderSchema]
To know which columns orders actually has, you have to go find OrderSchema. This extension
adds the columns to the same hover:
OrderSchema — models/orders.py:9
id : Series[int]
customerId: Series[int]
couponId : Optional[Series[pd.Int64Dtype]] # nullable=True
status : Series[str] # isin=["OPEN", "SHIPPED", "CANCELLED"]
total : Series[float] # ge=0
Features
- Works anywhere the type shows up: variables, function parameters, return values,
attributes. If the hover says
DataFrame[Schema], you get the columns.
- Always current: columns are read from the schema's source on every hover, including
unsaved edits. There's no copy that can drift.
- Inheritance: a schema that subclasses another one shows the inherited columns too.
Field(...) constraints like nullable=True, ge=0 and isin=[...] are shown next to
each column.- Jump to the schema: the schema name in the hover links to its definition.
- pandas, Polars and GeoPandas:
DataFrame[...], LazyFrame[...] and
GeoDataFrame[...] from pandera.typing are all recognised.
- Read-only and safe: it never runs your code or imports Python. It only reads source text,
so it also works in untrusted workspaces.
Requirements
A Python language server that shows types on hover. Pylance (the default with the
Microsoft Python extension) and basedpyright both work. The extension adds to their hover
and doesn't replace it.
Your variables need a pandera type the language server can see, e.g.
def load() -> DataFrame[OrderSchema] or orders: DataFrame[OrderSchema] = .... A plain
pd.DataFrame has no schema to show.
Settings
| Setting |
Default |
Description |
panderaHover.exclude |
venv, .venv, node_modules, site-packages, __pycache__ |
Globs skipped when a schema has to be found by scanning .py files. Scanning is only a fallback, used when the language server's workspace symbols don't find the class. Add large data or vendored folders here. |
Known limitations
- If two schema classes share a name, the one in the current file wins, then any in your
workspace. Otherwise the first one found is shown.
- Columns are read from the class body as written. Columns added dynamically at runtime aren't
shown.
Contributing
Issues and PRs are welcome at
github.com/liadyar/pandera-hover.
npm test # parser tests: plain node, no VS Code needed
npm run package # builds pandera-hover-<version>.vsix
To try a local build: code --install-extension pandera-hover-<version>.vsix --force, then
Developer: Reload Window.
License
MIT
