docs(python): Add docstring examples for reading json (#14481)

Co-authored-by: Ned Western <[email protected]>

py-polars/polars/io/json.py

@@ -55,6 +55,36 @@ def read_json(
     See Also
     --------
     read_ndjson
+
+    Examples
+    --------
+    >>> from io import StringIO
+    >>> json_str = '[{"foo":1,"bar":6},{"foo":2,"bar":7},{"foo":3,"bar":8}]'
+    >>> pl.read_json(StringIO(json_str))
+    shape: (3, 2)
+    ┌─────┬─────┐
+    │ foo ┆ bar │
+    │ --- ┆ --- │
+    │ i64 ┆ i64 │
+    ╞═════╪═════╡
+    │ 1   ┆ 6   │
+    │ 2   ┆ 7   │
+    │ 3   ┆ 8   │
+    └─────┴─────┘
+
+    With the schema defined.
+
+    >>> pl.read_json(StringIO(json_str), schema={"foo": pl.Int64, "bar": pl.Float64})
+    shape: (3, 2)
+    ┌─────┬─────┐
+    │ foo ┆ bar │
+    │ --- ┆ --- │
+    │ i64 ┆ f64 │
+    ╞═════╪═════╡
+    │ 1   ┆ 6.0 │
+    │ 2   ┆ 7.0 │
+    │ 3   ┆ 8.0 │
+    └─────┴─────┘
     """
     if isinstance(source, StringIO):
         source = BytesIO(source.getvalue().encode())

py-polars/polars/io/ndjson.py

@@ -28,7 +28,7 @@ def read_ndjson(
     schema_overrides: SchemaDefinition | None = None,
     ignore_errors: bool = False,
 ) -> DataFrame:
-    """
+    r"""
     Read into a DataFrame from a newline delimited JSON file.
 
     Parameters
@@ -52,6 +52,22 @@ def read_ndjson(
         any dtypes inferred from the schema param will be overridden.
     ignore_errors
         Return `Null` if parsing fails because of schema mismatches.
+
+    Examples
+    --------
+    >>> from io import StringIO
+    >>> json_str = '{"foo":1,"bar":6}\n{"foo":2,"bar":7}\n{"foo":3,"bar":8}\n'
+    >>> pl.read_ndjson(StringIO(json_str))
+    shape: (3, 2)
+    ┌─────┬─────┐
+    │ foo ┆ bar │
+    │ --- ┆ --- │
+    │ i64 ┆ i64 │
+    ╞═════╪═════╡
+    │ 1   ┆ 6   │
+    │ 2   ┆ 7   │
+    │ 3   ┆ 8   │
+    └─────┴─────┘
     """
     if isinstance(source, StringIO):
         source = BytesIO(source.getvalue().encode())