pyarrow.ChunkedArray#

classpyarrow.ChunkedArray#

Bases:_PandasConvertible

An array-like composed from a (possibly empty) collection of pyarrow.Arrays

Warning

Do not call this class’s constructor directly.

Examples

To construct a ChunkedArray object usepyarrow.chunked_array():

>>>importpyarrowaspa>>>pa.chunked_array([],type=pa.int8())<pyarrow.lib.ChunkedArray object at ...>[...]

>>>pa.chunked_array([[2,2,4],[4,5,100]])<pyarrow.lib.ChunkedArray object at ...>[  [    2,    2,    4  ],  [    4,    5,    100  ]]>>>isinstance(pa.chunked_array([[2,2,4],[4,5,100]]),pa.ChunkedArray)True

__init__(*args,**kwargs)#

Methods

__init__(*args, **kwargs)
cast(self[, target_type, safe, options])	Cast array values to another data type
chunk(self, i)	Select a chunk by its index.
combine_chunks(self, MemoryPool memory_pool=None)	Flatten this ChunkedArray into a single non-chunked array.
dictionary_encode(self[, null_encoding])	Compute dictionary-encoded representation of array.
drop_null(self)	Remove missing values from a chunked array.
equals(self, ChunkedArray other)	Return whether the contents of two chunked arrays are equal.
fill_null(self, fill_value)	Replace each null element in values with fill_value.
filter(self, mask[, null_selection_behavior])	Select values from the chunked array.
flatten(self, MemoryPool memory_pool=None)	Flatten this ChunkedArray.
format(self, **kwargs)	DEPRECATED, use pyarrow.ChunkedArray.to_string
get_total_buffer_size(self)	The sum of bytes in each buffer referenced by the chunked array.
index(self, value[, start, end, memory_pool])	Find the first index of a value.
is_nan(self)	Return boolean array indicating the NaN values.
is_null(self, *[, nan_is_null])	Return boolean array indicating the null values.
is_valid(self)	Return boolean array indicating the non-null values.
iterchunks(self)	Convert to an iterator of ChunkArrays.
length(self)	Return length of a ChunkedArray.
slice(self[, offset, length])	Compute zero-copy slice of this ChunkedArray
sort(self[, order])	Sort the ChunkedArray
take(self, indices)	Select values from the chunked array.
to_numpy(self[, zero_copy_only])	Return a NumPy copy of this array (experimental).
to_pandas(self[, memory_pool, categories, ...])	Convert to a pandas-compatible NumPy array or DataFrame, as appropriate
to_pylist(self, *[, maps_as_pydicts])	Convert to a list of native Python objects.
to_string(self, *, int indent=0, ...)	Render a "pretty-printed" string representation of the ChunkedArray
unify_dictionaries(self, ...)	Unify dictionaries across all chunks.
unique(self)	Compute distinct elements in array
validate(self, *[, full])	Perform validation checks.
value_counts(self)	Compute counts of unique elements in array.

Attributes

chunks	Convert to a list of single-chunked arrays.
data
is_cpu	Whether all chunks in the ChunkedArray are CPU-accessible.
nbytes	Total number of bytes consumed by the elements of the chunked array.
null_count	Number of null entries
num_chunks	Number of underlying chunks.
type	Return data type of a ChunkedArray.

cast(self,target_type=None,safe=None,options=None)#

Cast array values to another data type

Seepyarrow.compute.cast() for usage.

Parameters:

target_typeDataType,None

Type to cast array to.

safebool, defaultTrue

Whether to check for conversion errors such as overflow.

optionsCastOptions, defaultNone

Additional checks pass by CastOptions

Returns:

castArray orChunkedArray

Examples

>>>importpyarrowaspa>>>n_legs=pa.chunked_array([[2,2,4],[4,5,100]])>>>n_legs.typeDataType(int64)

Change the data type of an array:

>>>n_legs_seconds=n_legs.cast(pa.duration('s'))>>>n_legs_seconds.typeDurationType(duration[s])

chunk(self,i)#

Select a chunk by its index.

Parameters:

iint

Returns:

pyarrow.Array

Examples

>>>importpyarrowaspa>>>n_legs=pa.chunked_array([[2,2,None],[4,5,100]])>>>n_legs.chunk(1)<pyarrow.lib.Int64Array object at ...>[  4,  5,  100]

chunks#

Convert to a list of single-chunked arrays.

Examples

>>>importpyarrowaspa>>>n_legs=pa.chunked_array([[2,2,None],[4,5,100]])>>>n_legs<pyarrow.lib.ChunkedArray object at ...>[  [    2,    2,    null  ],  [    4,    5,    100  ]]>>>n_legs.chunks[<pyarrow.lib.Int64Array object at ...>[  2,  2,  null], <pyarrow.lib.Int64Array object at ...>[  4,  5,  100]]

combine_chunks(self,MemoryPoolmemory_pool=None)#

Flatten this ChunkedArray into a single non-chunked array.

Parameters:

memory_poolMemoryPool, defaultNone

For memory allocations, if required, otherwise use default pool

Returns:

resultArray

Examples

>>>importpyarrowaspa>>>n_legs=pa.chunked_array([[2,2,4],[4,5,100]])>>>n_legs<pyarrow.lib.ChunkedArray object at ...>[  [    2,    2,    4  ],  [    4,    5,    100  ]]>>>n_legs.combine_chunks()<pyarrow.lib.Int64Array object at ...>[  2,  2,  4,  4,  5,  100]

data#

dictionary_encode(self,null_encoding='mask')#

Compute dictionary-encoded representation of array.

Seepyarrow.compute.dictionary_encode() for full usage.

Parameters:

null_encodingstr, default “mask”

How to handle null entries.

Returns:

encodedChunkedArray

A dictionary-encoded version of this array.

Examples

>>>importpyarrowaspa>>>animals=pa.chunked_array((...["Flamingo","Parrot","Dog"],...["Horse","Brittle stars","Centipede"]...))>>>animals.dictionary_encode()<pyarrow.lib.ChunkedArray object at ...>[...  -- dictionary:    [      "Flamingo",      "Parrot",      "Dog",      "Horse",      "Brittle stars",      "Centipede"    ]  -- indices:    [      0,      1,      2    ],...  -- dictionary:    [      "Flamingo",      "Parrot",      "Dog",      "Horse",      "Brittle stars",      "Centipede"    ]  -- indices:    [      3,      4,      5    ]]

drop_null(self)#

Remove missing values from a chunked array.Seepyarrow.compute.drop_null() for full description.

Examples

>>>importpyarrowaspa>>>n_legs=pa.chunked_array([[2,2,None],[4,5,100]])>>>n_legs<pyarrow.lib.ChunkedArray object at ...>[  [    2,    2,    null  ],  [    4,    5,    100  ]]>>>n_legs.drop_null()<pyarrow.lib.ChunkedArray object at ...>[  [    2,    2  ],  [    4,    5,    100  ]]

equals(self,ChunkedArrayother)#

Return whether the contents of two chunked arrays are equal.

Parameters:

otherpyarrow.ChunkedArray

Chunked array to compare against.

Returns:

are_equalbool

Examples

>>>importpyarrowaspa>>>n_legs=pa.chunked_array([[2,2,4],[4,5,100]])>>>animals=pa.chunked_array((...["Flamingo","Parrot","Dog"],...["Horse","Brittle stars","Centipede"]...))>>>n_legs.equals(n_legs)True>>>n_legs.equals(animals)False

fill_null(self,fill_value)#

Replace each null element in values with fill_value.

Seepyarrow.compute.fill_null() for full usage.

Parameters:

fill_valueany

The replacement value for null entries.

Returns:

resultArray orChunkedArray

A new array with nulls replaced by the given value.

Examples

>>>importpyarrowaspa>>>fill_value=pa.scalar(5,type=pa.int8())>>>n_legs=pa.chunked_array([[2,2,4],[4,None,100]])>>>n_legs.fill_null(fill_value)<pyarrow.lib.ChunkedArray object at ...>[  [    2,    2,    4,    4,    5,    100  ]]

filter(self,mask,null_selection_behavior='drop')#

Select values from the chunked array.

Seepyarrow.compute.filter() for full usage.

Parameters:

maskArray orarray-like

The boolean mask to filter the chunked array with.

null_selection_behaviorstr, default “drop”

How nulls in the mask should be handled.

Returns:

filteredArray orChunkedArray

An array of the same type, with only the elements selected bythe boolean mask.

Examples

>>>importpyarrowaspa>>>n_legs=pa.chunked_array([[2,2,4],[4,5,100]])>>>n_legs<pyarrow.lib.ChunkedArray object at ...>[  [    2,    2,    4  ],  [    4,    5,    100  ]]>>>mask=pa.array([True,False,None,True,False,True])>>>n_legs.filter(mask)<pyarrow.lib.ChunkedArray object at ...>[  [    2  ],  [    4,    100  ]]>>>n_legs.filter(mask,null_selection_behavior="emit_null")<pyarrow.lib.ChunkedArray object at ...>[  [    2,    null  ],  [    4,    100  ]]

flatten(self,MemoryPoolmemory_pool=None)#

Flatten this ChunkedArray. If it has a struct type, the column isflattened into one array per struct field.

Parameters:

memory_poolMemoryPool, defaultNone

For memory allocations, if required, otherwise use default pool

Returns:

resultlist ofChunkedArray

Examples

>>>importpyarrowaspa>>>n_legs=pa.chunked_array([[2,2,4],[4,5,100]])>>>c_arr=pa.chunked_array(n_legs.value_counts())>>>c_arr<pyarrow.lib.ChunkedArray object at ...>[  -- is_valid: all not null  -- child 0 type: int64    [      2,      4,      5,      100    ]  -- child 1 type: int64    [      2,      2,      1,      1    ]]>>>c_arr.flatten()[<pyarrow.lib.ChunkedArray object at ...>[  [    2,    4,    5,    100  ]], <pyarrow.lib.ChunkedArray object at ...>[  [    2,    2,    1,    1  ]]]>>>c_arr.typeStructType(struct<values: int64, counts: int64>)>>>n_legs.typeDataType(int64)

format(self,**kwargs)#

DEPRECATED, use pyarrow.ChunkedArray.to_string

Parameters:

**kwargsdict

Returns:

str

get_total_buffer_size(self)#

The sum of bytes in each buffer referenced by the chunked array.

An array may only reference a portion of a buffer.This method will overestimate in this case and return thebyte size of the entire buffer.

If a buffer is referenced multiple times then it willonly be counted once.

Examples

>>>importpyarrowaspa>>>n_legs=pa.chunked_array([[2,2,4],[4,None,100]])>>>n_legs.get_total_buffer_size()49

index(self,value,start=None,end=None,*,memory_pool=None)#

Find the first index of a value.

Seepyarrow.compute.index() for full usage.

Parameters:

valueScalar or object

The value to look for in the array.

startint, optional

The start index where to look forvalue.

endint, optional

The end index where to look forvalue.

memory_poolMemoryPool, optional

A memory pool for potential memory allocations.

Returns:

indexInt64Scalar

The index of the value in the array (-1 if not found).

Examples

>>>importpyarrowaspa>>>n_legs=pa.chunked_array([[2,2,4],[4,5,100]])>>>n_legs<pyarrow.lib.ChunkedArray object at ...>[  [    2,    2,    4  ],  [    4,    5,    100  ]]>>>n_legs.index(4)<pyarrow.Int64Scalar: 2>>>>n_legs.index(4,start=3)<pyarrow.Int64Scalar: 3>

is_cpu#

Whether all chunks in the ChunkedArray are CPU-accessible.

is_nan(self)#

Return boolean array indicating the NaN values.

Examples

>>>importpyarrowaspa>>>importnumpyasnp>>>arr=pa.chunked_array([[2,np.nan,4],[4,None,100]])>>>arr.is_nan()<pyarrow.lib.ChunkedArray object at ...>[  [    false,    true,    false,    false,    null,    false  ]]

is_null(self,*,nan_is_null=False)#

Return boolean array indicating the null values.

Parameters:

nan_is_nullbool (optional, defaultFalse)

Whether floating-point NaN values should also be considered null.

Returns:

arrayboolArray orChunkedArray

Examples

>>>importpyarrowaspa>>>n_legs=pa.chunked_array([[2,2,4],[4,None,100]])>>>n_legs.is_null()<pyarrow.lib.ChunkedArray object at ...>[  [    false,    false,    false,    false,    true,    false  ]]

is_valid(self)#

Return boolean array indicating the non-null values.

Examples

>>>importpyarrowaspa>>>n_legs=pa.chunked_array([[2,2,4],[4,None,100]])>>>n_legs.is_valid()<pyarrow.lib.ChunkedArray object at ...>[  [    true,    true,    true  ],  [    true,    false,    true  ]]

iterchunks(self)#

Convert to an iterator of ChunkArrays.

Examples

>>>importpyarrowaspa>>>n_legs=pa.chunked_array([[2,2,4],[4,None,100]])>>>foriinn_legs.iterchunks():...print(i.null_count)...01

length(self)#

Return length of a ChunkedArray.

Examples

>>>importpyarrowaspa>>>n_legs=pa.chunked_array([[2,2,4],[4,5,100]])>>>n_legs.length()6

nbytes#

Total number of bytes consumed by the elements of the chunked array.

In other words, the sum of bytes from all buffer ranges referenced.

Unlikeget_total_buffer_size this method will account for arrayoffsets.

If buffers are shared between arrays then the sharedportion will only be counted multiple times.

The dictionary of dictionary arrays will always be counted in theirentirety even if the array only references a portion of the dictionary.

Examples

>>>importpyarrowaspa>>>n_legs=pa.chunked_array([[2,2,4],[4,None,100]])>>>n_legs.nbytes49

null_count#

Number of null entries

Returns:

int

Examples

>>>importpyarrowaspa>>>n_legs=pa.chunked_array([[2,2,4],[4,None,100]])>>>n_legs.null_count1

num_chunks#

Number of underlying chunks.

Returns:

int

Examples

>>>importpyarrowaspa>>>n_legs=pa.chunked_array([[2,2,None],[4,5,100]])>>>n_legs.num_chunks2

slice(self,offset=0,length=None)#

Compute zero-copy slice of this ChunkedArray

Parameters:

offsetint, default 0

Offset from start of array to slice

lengthint, defaultNone

Length of slice (default is until end of batch starting fromoffset)

Returns:

slicedChunkedArray

Examples

>>>importpyarrowaspa>>>n_legs=pa.chunked_array([[2,2,4],[4,5,100]])>>>n_legs<pyarrow.lib.ChunkedArray object at ...>[  [    2,    2,    4  ],  [    4,    5,    100  ]]>>>n_legs.slice(2,2)<pyarrow.lib.ChunkedArray object at ...>[  [    4  ],  [    4  ]]

sort(self,order='ascending',**kwargs)#

Sort the ChunkedArray

Parameters:

orderstr, default “ascending”

Which order to sort values in.Accepted values are “ascending”, “descending”.

**kwargsdict, optional

Additional sorting options.As allowed bySortOptions

Returns:

resultChunkedArray

take(self,indices)#

Select values from the chunked array.

Seepyarrow.compute.take() for full usage.

Parameters:

indicesArray orarray-like

The indices in the array whose values will be returned.

Returns:

takenArray orChunkedArray

An array with the same datatype, containing the taken values.

Examples

>>>importpyarrowaspa>>>n_legs=pa.chunked_array([[2,2,4],[4,5,100]])>>>n_legs<pyarrow.lib.ChunkedArray object at ...>[  [    2,    2,    4  ],  [    4,    5,    100  ]]>>>n_legs.take([1,4,5])<pyarrow.lib.ChunkedArray object at ...>[  [    2,    5,    100  ]]

to_numpy(self,zero_copy_only=False)#

Return a NumPy copy of this array (experimental).

Parameters:

zero_copy_onlybool, defaultFalse

Introduced for signature consistence with pyarrow.Array.to_numpy.This must be False here since NumPy arrays’ buffer must be contiguous.

Returns:

arraynumpy.ndarray

Examples

>>>importpyarrowaspa>>>n_legs=pa.chunked_array([[2,2,4],[4,5,100]])>>>n_legs.to_numpy()array([  2,   2,   4,   4,   5, 100])

to_pandas(self,memory_pool=None,categories=None,boolstrings_to_categorical=False,boolzero_copy_only=False,boolinteger_object_nulls=False,booldate_as_object=True,booltimestamp_as_object=False,booluse_threads=True,booldeduplicate_objects=True,boolignore_metadata=False,boolsafe=True,boolsplit_blocks=False,boolself_destruct=False,strmaps_as_pydicts=None,types_mapper=None,boolcoerce_temporal_nanoseconds=False)#

Convert to a pandas-compatible NumPy array or DataFrame, as appropriate

Parameters:

memory_poolMemoryPool, defaultNone

Arrow MemoryPool to use for allocations. Uses the default memorypool if not passed.

categorieslist, defaultempty

List of fields that should be returned as pandas.Categorical. Onlyapplies to table-like data structures.

strings_to_categoricalbool, defaultFalse

Encode string (UTF8) and binary types to pandas.Categorical.

zero_copy_onlybool, defaultFalse

Raise an ArrowException if this function call would require copyingthe underlying data.

integer_object_nullsbool, defaultFalse

Cast integers with nulls to objects

date_as_objectbool, defaultTrue

Cast dates to objects. If False, convert to datetime64 dtype withthe equivalent time unit (if supported). Note: in pandas version< 2.0, only datetime64[ns] conversion is supported.

timestamp_as_objectbool, defaultFalse

Cast non-nanosecond timestamps (np.datetime64) to objects. This isuseful in pandas version 1.x if you have timestamps that don’t fitin the normal date range of nanosecond timestamps (1678 CE-2262 CE).Non-nanosecond timestamps are supported in pandas version 2.0.If False, all timestamps are converted to datetime64 dtype.

use_threadsbool, defaultTrue

Whether to parallelize the conversion using multiple threads.

deduplicate_objectsbool, defaultTrue

Do not create multiple copies Python objects when created, to saveon memory use. Conversion will be slower.

ignore_metadatabool, defaultFalse

If True, do not use the ‘pandas’ metadata to reconstruct theDataFrame index, if present

safebool, defaultTrue

For certain data types, a cast is needed in order to store thedata in a pandas DataFrame or Series (e.g. timestamps are alwaysstored as nanoseconds in pandas). This option controls whether itis a safe cast or not.

split_blocksbool, defaultFalse

If True, generate one internal “block” for each column whencreating a pandas.DataFrame from a RecordBatch or Table. While thiscan temporarily reduce memory note that various pandas operationscan trigger “consolidation” which may balloon memory use.

self_destructbool, defaultFalse

EXPERIMENTAL: If True, attempt to deallocate the originating Arrowmemory while converting the Arrow object to pandas. If you use theobject after calling to_pandas with this option it will crash yourprogram.

Note that you may not see always memory usage improvements. Forexample, if multiple columns share an underlying allocation,memory can’t be freed until all columns are converted.

maps_as_pydictsstr, optional, defaultNone

Valid values areNone, ‘lossy’, or ‘strict’.The default behavior (None), is to convert Arrow Map arrays toPython association lists (list-of-tuples) in the same order as theArrow Map, as in [(key1, value1), (key2, value2), …].

If ‘lossy’ or ‘strict’, convert Arrow Map arrays to native Python dicts.This can change the ordering of (key, value) pairs, and willdeduplicate multiple keys, resulting in a possible loss of data.

If ‘lossy’, this key deduplication results in a warning printedwhen detected. If ‘strict’, this instead results in an exceptionbeing raised when detected.

types_mapperfunction, defaultNone

A function mapping a pyarrow DataType to a pandas ExtensionDtype.This can be used to override the default pandas type for conversionof built-in pyarrow types or in absence of pandas_metadata in theTable schema. The function receives a pyarrow DataType and isexpected to return a pandas ExtensionDtype orNone if thedefault conversion should be used for that type. If you havea dictionary mapping, you can passdict.get as function.

coerce_temporal_nanosecondsbool, defaultFalse

Only applicable to pandas version >= 2.0.A legacy option to coerce date32, date64, duration, and timestamptime units to nanoseconds when converting to pandas. This is thedefault behavior in pandas version 1.x. Set this option to True ifyou’d like to use this coercion when using pandas version >= 2.0for backwards compatibility (not recommended otherwise).

Returns:

pandas.Series orpandas.DataFrame depending ontype of object

Examples

>>>importpyarrowaspa>>>importpandasaspd

Convert a Table to pandas DataFrame:

>>>table=pa.table([...pa.array([2,4,5,100]),...pa.array(["Flamingo","Horse","Brittle stars","Centipede"])...],names=['n_legs','animals'])>>>table.to_pandas()   n_legs        animals0       2       Flamingo1       4          Horse2       5  Brittle stars3     100      Centipede>>>isinstance(table.to_pandas(),pd.DataFrame)True

Convert a RecordBatch to pandas DataFrame:

>>>importpyarrowaspa>>>n_legs=pa.array([2,4,5,100])>>>animals=pa.array(["Flamingo","Horse","Brittle stars","Centipede"])>>>batch=pa.record_batch([n_legs,animals],...names=["n_legs","animals"])>>>batchpyarrow.RecordBatchn_legs: int64animals: string----n_legs: [2,4,5,100]animals: ["Flamingo","Horse","Brittle stars","Centipede"]>>>batch.to_pandas()   n_legs        animals0       2       Flamingo1       4          Horse2       5  Brittle stars3     100      Centipede>>>isinstance(batch.to_pandas(),pd.DataFrame)True

Convert a Chunked Array to pandas Series:

>>>importpyarrowaspa>>>n_legs=pa.chunked_array([[2,2,4],[4,5,100]])>>>n_legs.to_pandas()0      21      22      43      44      55    100dtype: int64>>>isinstance(n_legs.to_pandas(),pd.Series)True

to_pylist(self,*,maps_as_pydicts=None)#

Convert to a list of native Python objects.

Parameters:

maps_as_pydictsstr, optional, defaultNone

Valid values areNone, ‘lossy’, or ‘strict’.The default behavior (None), is to convert Arrow Map arrays toPython association lists (list-of-tuples) in the same order as theArrow Map, as in [(key1, value1), (key2, value2), …].

If ‘lossy’ or ‘strict’, convert Arrow Map arrays to native Python dicts.

If ‘lossy’, whenever duplicate keys are detected, a warning will be printed.The last seen value of a duplicate key will be in the Python dictionary.If ‘strict’, this instead results in an exception being raised when detected.

Examples

>>>importpyarrowaspa>>>n_legs=pa.chunked_array([[2,2,4],[4,None,100]])>>>n_legs.to_pylist()[2, 2, 4, 4, None, 100]

to_string(self,*,intindent=0,intwindow=5,intcontainer_window=2,boolskip_new_lines=False,intelement_size_limit=100)#

Render a “pretty-printed” string representation of the ChunkedArray

Parameters:

indentint

How much to indent right the content of the array,by default0.

windowint

How many items to preview within each chunk at the begin and endof the chunk when the chunk is bigger than the window.The other elements will be ellipsed.

container_windowint

How many chunks to preview at the begin and endof the array when the array is bigger than the window.The other elements will be ellipsed.This setting also applies to list columns.

skip_new_linesbool

If the array should be rendered as a single line of textor if each element should be on its own line.

element_size_limitint, default 100

Maximum number of characters of a single element before it is truncated.

Examples

>>>importpyarrowaspa>>>n_legs=pa.chunked_array([[2,2,4],[4,5,100]])>>>n_legs.to_string(skip_new_lines=True)'[[2,2,4],[4,5,100]]'

type#

Return data type of a ChunkedArray.

Examples

>>>importpyarrowaspa>>>n_legs=pa.chunked_array([[2,2,4],[4,5,100]])>>>n_legs.typeDataType(int64)

unify_dictionaries(self,MemoryPoolmemory_pool=None)#

Unify dictionaries across all chunks.

This method returns an equivalent chunked array, but where allchunks share the same dictionary values. Dictionary indices aretransposed accordingly.

If there are no dictionaries in the chunked array, it is returnedunchanged.

Parameters:

memory_poolMemoryPool, defaultNone

For memory allocations, if required, otherwise use default pool

Returns:

resultChunkedArray

Examples

>>>importpyarrowaspa>>>arr_1=pa.array(["Flamingo","Parrot","Dog"]).dictionary_encode()>>>arr_2=pa.array(["Horse","Brittle stars","Centipede"]).dictionary_encode()>>>c_arr=pa.chunked_array([arr_1,arr_2])>>>c_arr<pyarrow.lib.ChunkedArray object at ...>[...  -- dictionary:    [      "Flamingo",      "Parrot",      "Dog"    ]  -- indices:    [      0,      1,      2    ],...  -- dictionary:    [      "Horse",      "Brittle stars",      "Centipede"    ]  -- indices:    [      0,      1,      2    ]]>>>c_arr.unify_dictionaries()<pyarrow.lib.ChunkedArray object at ...>[...  -- dictionary:    [      "Flamingo",      "Parrot",      "Dog",      "Horse",      "Brittle stars",      "Centipede"    ]  -- indices:    [      0,      1,      2    ],...  -- dictionary:    [      "Flamingo",      "Parrot",      "Dog",      "Horse",      "Brittle stars",      "Centipede"    ]  -- indices:    [      3,      4,      5    ]]

unique(self)#

Compute distinct elements in array

Returns:

pyarrow.Array

Examples

>>>importpyarrowaspa>>>n_legs=pa.chunked_array([[2,2,4],[4,5,100]])>>>n_legs<pyarrow.lib.ChunkedArray object at ...>[  [    2,    2,    4  ],  [    4,    5,    100  ]]>>>n_legs.unique()<pyarrow.lib.Int64Array object at ...>[  2,  4,  5,  100]

validate(self,*,full=False)#

Perform validation checks. An exception is raised if validation fails.

By default only cheap validation checks are run. Passfull=Truefor thorough validation checks (potentially O(n)).

Parameters:

fullbool, defaultFalse

If True, run expensive checks, otherwise cheap checks only.

Raises:

ArrowInvalid

value_counts(self)#

Compute counts of unique elements in array.

Returns:

Anarray of <inputtype “Values”,int64_t “Counts”>structs

Examples

>>>importpyarrowaspa>>>n_legs=pa.chunked_array([[2,2,4],[4,5,100]])>>>n_legs<pyarrow.lib.ChunkedArray object at ...>[  [    2,    2,    4  ],  [    4,    5,    100  ]]>>>n_legs.value_counts()<pyarrow.lib.StructArray object at ...>-- is_valid: all not null-- child 0 type: int64  [    2,    4,    5,    100  ]-- child 1 type: int64  [    2,    2,    1,    1  ]