Closed riley-harper closed 5 months ago
Can reproduce.
It seems something is up with slice_pushdown
on the streaming engine.
>>> lf.slice(0, 4).collect(streaming=True, slice_pushdown=False)
shape: (3, 1)
┌─────┐
│ A │
│ --- │
│ i64 │
╞═════╡
│ 1 │
│ 2 │
│ 3 │
└─────┘
Update: It seems to be specific to the frame method, Expr.slice is ok:
>>> lf.select(pl.all().slice(0, 4)).collect(streaming=True)
shape: (3, 1)
┌─────┐
│ A │
│ --- │
│ i64 │
╞═════╡
│ 1 │
│ 2 │
│ 3 │
└─────┘
Checks
Reproducible example
The exception traceback (with RUST_BACKTRACE=1) is
Log output
Issue description
In the specific case where I use
scan_csv()
with a*.csv
glob,LazyFrame.slice()
, andcollect()
with streaming set to True, I get a PanicException. If I set streaming to False, or don't callLazyFrame.slice()
before collecting, I get the result I expect, not a panic.Expected behavior
I would expect that the result with streaming=True would be the same as with streaming=False, which is a DataFrame that looks like
Installed versions