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Beacon Python SDK ​

Beacon has an official Python client library. Use it to explore a server and to run queries. You build no HTTP request by hand.

The SDK documentation is here:

Install ​

bash
pip install beacon-api

Import the client:

python
from beacon_api import Client

Connect to a Beacon node ​

Create a client with the base URL of your Beacon server:

python
from beacon_api import Client

client = Client(
    "https://beacon.example.com",
    # jwt_token="<optional bearer token>",
    # proxy_headers={"X-Forwarded-For": "<optional ip>"},
    # basic_auth=("user", "pass"),
)

client.check_status()  # probes /api/health and prints the Beacon version
info = client.get_server_info()  # metadata from /api/info
print(info.get("beacon_version"))

Explore tables ​

list_tables() returns a map. It maps each table name to a DataTable helper.

python
tables = client.list_tables()

for name, table in tables.items():
    print(name, table.get_table_type(), table.get_table_description())

Inspect the Arrow schema of a table:

python
default_table = tables["default"]

schema = default_table.get_table_schema_arrow()
for field in schema:
    print(f"{field.name}: {field.type}")

Explore datasets (Beacon 1.4.0 and later) ​

Does your node list datasets? Then you can query the files directly. You create no table first.

python
datasets = client.list_datasets(pattern="**/*.parquet", limit=10)
first = next(iter(datasets.values()))

print(first.get_file_path(), first.get_file_format())
schema = first.get_schema()

Start from a table or a dataset. Then chain the selects and the filters.

python
stations = client.list_tables()["default"]

df = (
    stations
    .query()
    .add_select_columns([
        ("LONGITUDE", None),
        ("LATITUDE", None),
        ("JULD", None),
        ("TEMP", "temperature_c"),
    ])
    .add_range_filter("JULD", "2024-01-01T00:00:00", "2024-06-30T23:59:59")
    .to_pandas_dataframe()
)

print(df.head())

Expressions and functions ​

The SDK gives helpers for common server-side expressions:

python
from beacon_api.query import Functions

query = (
    stations
    .query()
    .add_select_column("CRUISE")
    .add_select_column("STATION")
    .add_select(Functions.concat(["CRUISE", "STATION"], alias="cast_id"))
    .add_select(Functions.try_cast_to_type("TEMP", to_type="float64", alias="temp_float"))
)

Multiple filters ​

python
filtered = (
    stations
    .query()
    .add_select_column("LONGITUDE")
    .add_select_column("LATITUDE")
    .add_select_column("JULD")
    .add_select_column("TEMP")
    .add_equals_filter("DATA_TYPE", "CTD")
    .add_range_filter("PRES", 0, 10)
    .add_bbox_filter("LONGITUDE", "LATITUDE", bbox=(-20, 40, -10, 55))
)

For your own boolean logic, combine filter nodes. Then give them to add_filter():

python
from beacon_api.query import AndFilter, RangeFilter

filtered = filtered.add_filter(
    AndFilter([
        RangeFilter("TEMP", gt_eq=-2, lt_eq=35),
        RangeFilter("PSAL", gt_eq=30, lt_eq=40),
    ])
)

Distinct and sort ​

python
query = (
    stations
    .query()
    .add_select_column("CRUISE")
    .add_select_column("STATION")
    .add_select_column("JULD")
    .set_distinct(["CRUISE", "STATION"])
    .add_sort("JULD", ascending=True)
)

Explain the plan ​

explain() calls the /api/explain-query endpoint of Beacon. You then see the plan of the server for your request.

python
plan = query.explain()
print(plan)

Export results (Pandas, GeoPandas, Parquet, NetCDF and more) ​

A query returns a common Python data structure. It also writes directly to disk.

python
query = (
    stations
    .query()
    .add_select_column("LONGITUDE")
    .add_select_column("LATITUDE")
    .add_select_column("JULD")
    .add_select_column("TEMP")
    .add_range_filter("JULD", "2024-01-01T00:00:00", "2024-01-31T23:59:59")
)

df = query.to_pandas_dataframe()
gdf = query.to_geo_pandas_dataframe("LONGITUDE", "LATITUDE")

query.to_parquet("subset.parquet")
query.to_geoparquet("subset.geoparquet", "LONGITUDE", "LATITUDE")
query.to_csv("subset.csv")

TIP

Does your Beacon node support server-side NdNetCDF? That needs Beacon 1.5.0 or later. Then export with to_nd_netcdf(path, dimension_columns=[...]).

Query with SQL ​

Do you already have SQL? Then build an SQLQuery. It uses the same output helpers:

python
sql = client.sql_query(
    """
    SELECT LONGITUDE, LATITUDE, JULD, TEMP AS temperature_c
    FROM default
    WHERE JULD BETWEEN '2024-01-01 00:00:00' AND '2024-06-30 23:59:59'
    ORDER BY JULD ASC
    """
)

df = sql.to_pandas_dataframe()
sql.to_parquet("slice.parquet")

More SDK docs ​

Released under the AGPL-3.0 License.

Copyright © MARIS & the Beacon contributors