polars.DataFrame.lazy

DataFrame.lazy() → LazyFrame

Start a lazy query from this point. This returns a LazyFrame object.

Operations on a LazyFrame are not executed until this is triggered by calling one of:

• .collect()

  (run on all data)

• .explain()

  (print the query plan)

• .show_graph()

  (show the query plan as graphviz graph)

• .collect_schema()

  (return the final frame schema)

Lazy operations are recommended because they allow for query optimization and additional parallelism.

Returns:

LazyFrame

Examples

>>> df = pl.DataFrame(
...     {
...         "a": [None, 2, 3, 4],
...         "b": [0.5, None, 2.5, 13],
...         "c": [True, True, False, None],
...     }
... )
>>> df.lazy()
<LazyFrame at ...>