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Polars is a blazingly fast DataFrames library implemented in Rust using Apache Arrow Columnar Format as memory model.
- Lazy | eager execution
- Multi-threaded
- SIMD
- Query optimization
- Powerful expression API
- Rust | Python | ...
To learn more, read the User Guide.
>>> import qadataframe as pl
>>> df = pl.DataFrame(
... {
... "A": [1, 2, 3, 4, 5],
... "fruits": ["banana", "banana", "apple", "apple", "banana"],
... "B": [5, 4, 3, 2, 1],
... "cars": ["beetle", "audi", "beetle", "beetle", "beetle"],
... }
... )
# embarrassingly parallel execution
# very expressive query language
>>> (
... df
... .sort("fruits")
... .select(
... [
... "fruits",
... "cars",
... pl.lit("fruits").alias("literal_string_fruits"),
... pl.col("B").filter(pl.col("cars") == "beetle").sum(),
... pl.col("A").filter(pl.col("B") > 2).sum().over("cars").alias("sum_A_by_cars"), # groups by "cars"
... pl.col("A").sum().over("fruits").alias("sum_A_by_fruits"), # groups by "fruits"
... pl.col("A").reverse().over("fruits").flatten().alias("rev_A_by_fruits"), # groups by "fruits
... pl.col("A").sort_by("B").over("fruits").flatten().alias("sort_A_by_B_by_fruits"), # groups by "fruits"
... ]
... )
... )
shape: (5, 8)
┌──────────┬──────────┬──────────────┬─────┬─────────────┬─────────────┬─────────────┬─────────────┐
│ fruits ┆ cars ┆ literal_stri ┆ B ┆ sum_A_by_ca ┆ sum_A_by_fr ┆ rev_A_by_fr ┆ sort_A_by_B │
│ --- ┆ --- ┆ ng_fruits ┆ --- ┆ rs ┆ uits ┆ uits ┆ _by_fruits │
│ str ┆ str ┆ --- ┆ i64 ┆ --- ┆ --- ┆ --- ┆ --- │
│ ┆ ┆ str ┆ ┆ i64 ┆ i64 ┆ i64 ┆ i64 │
╞══════════╪══════════╪══════════════╪═════╪═════════════╪═════════════╪═════════════╪═════════════╡
│ "apple" ┆ "beetle" ┆ "fruits" ┆ 11 ┆ 4 ┆ 7 ┆ 4 ┆ 4 │
├╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌┤
│ "apple" ┆ "beetle" ┆ "fruits" ┆ 11 ┆ 4 ┆ 7 ┆ 3 ┆ 3 │
├╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌┤
│ "banana" ┆ "beetle" ┆ "fruits" ┆ 11 ┆ 4 ┆ 8 ┆ 5 ┆ 5 │
├╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌┤
│ "banana" ┆ "audi" ┆ "fruits" ┆ 11 ┆ 2 ┆ 8 ┆ 2 ┆ 2 │
├╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌┤
│ "banana" ┆ "beetle" ┆ "fruits" ┆ 11 ┆ 4 ┆ 8 ┆ 1 ┆ 1 │
└──────────┴──────────┴──────────────┴─────┴─────────────┴─────────────┴─────────────┴─────────────┘
Polars is very fast, and in fact is one of the best performing solutions available. See the results in h2oai's db-benchmark.
Install the latest polars version with:
$ pip3 install polars
Update existing polars installation to the lastest version with:
$ pip3 install -U polars
Releases happen quite often (weekly / every few days) at the moment, so updating polars regularily to get the latest bugfixes / features might not be a bad idea.
You can take latest release from crates.io
, or if you want to use the latest features / performance improvements
point to the master
branch of this repo.
polars = { git = "https://github.com/pola-rs/polars", rev = "<optional git tag>" }
Required Rust version >=1.58
Want to know about all the features Polars supports? Read the docs!
- Installation guide:
$ pip3 install polars
- Python documentation
- User guide
- Installation guide:
$ yarn install nodejs-polars
- Node documentation
- User guide
Want to contribute? Read our contribution guideline.
If you want a bleeding edge release or maximal performance you should compile polars from source.
This can be done by going through the following steps in sequence:
- Install the latest Rust compiler
- Install maturin:
$ pip3 install maturin
- Choose any of:
- Fastest binary, very long compile times:
$ cd qadataframe && maturin develop --rustc-extra-args="-C target-cpu=native" --release
- Fast binary, Shorter compile times:
$ cd qadataframe && maturin develop --rustc-extra-args="-C codegen-units=16 -C lto=thin -C target-cpu=native" --release
- Fastest binary, very long compile times:
Note that the Rust crate implementing the Python bindings is called qadataframe
to distinguish from the wrapped
Rust crate polars
itself. However, both the Python package and the Python module are named polars
, so you
can pip install polars
and import polars
.
Polars has transitioned to arrow2. Arrow2 is a faster and safer implementation of the Apache Arrow Columnar Format. Arrow2 also has a more granular code base, helping to reduce the compiler bloat.
See this example.
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