pyarrow.dictionary#

pyarrow.dictionary(index_type,value_type,boolordered=False)→DictionaryType#

Dictionary (categorical, or simply encoded) type.

Parameters:

index_typeDataType

value_typeDataType

orderedbool

Returns:

typeDictionaryType

Examples

Create an instance of dictionary type:

>>>importpyarrowaspa>>>pa.dictionary(pa.int64(),pa.utf8())DictionaryType(dictionary<values=string, indices=int64, ordered=0>)

Use dictionary type to create an array:

>>>pa.array(["a","b",None,"d"],pa.dictionary(pa.int64(),pa.utf8()))<pyarrow.lib.DictionaryArray object at ...>...-- dictionary:  [    "a",    "b",    "d"  ]-- indices:  [    0,    1,    null,    2  ]