pyarrow.table¶
- pyarrow.table(data, names=None, schema=None, metadata=None, nthreads=None)¶
Create a pyarrow.Table from a Python data structure or sequence of arrays.
- Parameters:
- data
pandas.DataFrame
,dict
,list
A DataFrame, mapping of strings to Arrays or Python lists, or list of arrays or chunked arrays.
- names
list
, defaultNone
Column names if list of arrays passed as data. Mutually exclusive with ‘schema’ argument.
- schema
Schema
, defaultNone
The expected schema of the Arrow Table. If not passed, will be inferred from the data. Mutually exclusive with ‘names’ argument. If passed, the output will have exactly this schema (raising an error when columns are not found in the data and ignoring additional data not specified in the schema, when data is a dict or DataFrame).
- metadata
dict
or Mapping, defaultNone
Optional metadata for the schema (if schema not passed).
- nthreads
int
, defaultNone
For pandas.DataFrame inputs: if greater than 1, convert columns to Arrow in parallel using indicated number of threads. By default, this follows
pyarrow.cpu_count()
(may use up to system CPU count threads).
- data
- Returns:
See also
Examples
>>> import pyarrow as pa >>> n_legs = pa.array([2, 4, 5, 100]) >>> animals = pa.array(["Flamingo", "Horse", "Brittle stars", "Centipede"]) >>> names = ["n_legs", "animals"]
Construct a Table from arrays:
>>> pa.table([n_legs, animals], names=names) pyarrow.Table n_legs: int64 animals: string ---- n_legs: [[2,4,5,100]] animals: [["Flamingo","Horse","Brittle stars","Centipede"]]
Construct a Table from arrays with metadata:
>>> my_metadata={"n_legs": "Number of legs per animal"} >>> pa.table([n_legs, animals], names=names, metadata = my_metadata).schema n_legs: int64 animals: string -- schema metadata -- n_legs: 'Number of legs per animal'
Construct a Table from pandas DataFrame:
>>> import pandas as pd >>> df = pd.DataFrame({'year': [2020, 2022, 2019, 2021], ... 'n_legs': [2, 4, 5, 100], ... 'animals': ["Flamingo", "Horse", "Brittle stars", "Centipede"]}) >>> pa.table(df) pyarrow.Table year: int64 n_legs: int64 animals: string ---- year: [[2020,2022,2019,2021]] n_legs: [[2,4,5,100]] animals: [["Flamingo","Horse","Brittle stars","Centipede"]]
Construct a Table from pandas DataFrame with pyarrow schema:
>>> my_schema = pa.schema([ ... pa.field('n_legs', pa.int64()), ... pa.field('animals', pa.string())], ... metadata={"n_legs": "Number of legs per animal"}) >>> pa.table(df, my_schema).schema n_legs: int64 animals: string -- schema metadata -- n_legs: 'Number of legs per animal' pandas: '{"index_columns": [], "column_indexes": [{"name": null, ...
Construct a Table from chunked arrays:
>>> n_legs = pa.chunked_array([[2, 2, 4], [4, 5, 100]]) >>> animals = pa.chunked_array([["Flamingo", "Parrot", "Dog"], ["Horse", "Brittle stars", "Centipede"]]) >>> table = pa.table([n_legs, animals], names=names) >>> table pyarrow.Table n_legs: int64 animals: string ---- n_legs: [[2,2,4],[4,5,100]] animals: [["Flamingo","Parrot","Dog"],["Horse","Brittle stars","Centipede"]]