Deltalake-python

Native Delta Lake binding for Python based on delta-rs.

Installation

pip install deltalake

NOTE: official binary wheels are linked against openssl statically for remote objection store communication. Please file Github issue to request for critical openssl upgrade.

Usage

Resolve partitions for current version of the DeltaTable:

>>> from deltalake import DeltaTable
>>> dt = DeltaTable("../rust/tests/data/delta-0.2.0")
>>> dt.version()
3
>>> dt.files()
['part-00000-cb6b150b-30b8-4662-ad28-ff32ddab96d2-c000.snappy.parquet', 'part-00000-7c2deba3-1994-4fb8-bc07-d46c948aa415-c000.snappy.parquet', 'part-00001-c373a5bd-85f0-4758-815e-7eb62007a15c-c000.snappy.parquet']

Convert DeltaTable into PyArrow Table and Pandas Dataframe:

>>> from deltalake import DeltaTable
>>> dt = DeltaTable("../rust/tests/data/simple_table")
>>> df = dt.to_pyarrow_table().to_pandas()
>>> df
   id
0   5
1   7
2   9
>>> df[df['id'] > 5]
   id
1   7
2   9

Time travel:

>>> from deltalake import DeltaTable
>>> dt = DeltaTable("../rust/tests/data/simple_table")
>>> dt.load_version(2)
>>> dt.to_pyarrow_table().to_pandas()
   id
0   5
1   7
2   9
3   5
4   6
5   7
6   8
7   9

Schema:

>>> from deltalake import DeltaTable
>>> dt = DeltaTable("../rust/tests/data/simple_table")
>>> dt.schema()
Schema(Field(id: DataType(long) nullable(True) metadata({})))
>>> dt.pyarrow_schema()
id: int64

Develop

maturin is used to build the python package.

To install development version of the package into your current Python environment:

$ maturin develop

Code are formatted with https://github.com/psf/black.

Build manylinux wheels

docker run -e PKG_CONFIG_PATH=/usr/local/lib64/pkgconfig -it -v `pwd`:/io apache/arrow-dev:amd64-centos-6.10-python-manylinux2010 bash
curl https://sh.rustup.rs -sSf | sh -s -- -y
source $HOME/.cargo/env
rustup default stable
cargo install --git https://github.com/PyO3/maturin.git --rev 98636cea89c328b3eba4ebb548124f75c8018200 maturin
cd /io/python
export PATH=/opt/python/cp37-cp37m/bin:/opt/python/cp38-cp38/bin:$PATH
maturin publish -b pyo3 --target x86_64-unknown-linux-gnu --no-sdist