Series in Arkouda

Like Pandas, Arkouda supports Series. The purpose and intended functionality remains the same in Arkouda, but are configured to be based on arkouda.pdarrays.

class arkouda.Series(data, name=None, index=None)

One-dimensional Arkouda array with axis labels.

Parameters:

• index (Union[pdarray, Strings, Tuple, List, Index, None]) – An array of indices associated with the data array. If not provided (or empty), it defaults to a range of ints whose size matches the size of the data.

• data (Union[Tuple, List, pdarray, TypeVar(Strings), Categorical, Series, SegArray, Series, Categorical]) – A 1D array-like. Must not be None.

Raises:

• TypeError – Raised if index is not a pdarray or Strings object. Raised if data is not a supported type.

• ValueError – Raised if the index size does not match the data size.

Notes

The Series class accepts either positional arguments or keyword arguments.

Positional arguments

• Series(data): data is provided and an index is generated automatically.

• Series(data, index): both data and index are provided.

Keyword arguments

• Series(data=..., index=...): index is optional but must match the size of data when provided.

Features

Series support the majority of functionality offered by pandas.Series.

Lookup

arkouda.Series.locate(self, key)

Lookup values by index label.

Parameters:

key (Union[int, pdarray, Index, Series, List, Tuple]) –

The key or keys to look up. This can be: - A scalar - A list of scalars - A list of lists (for MultiIndex) - A Series (in which case labels are preserved, and its values are used as keys)

Keys will be converted to Arkouda arrays as needed.

Returns:

A Series containing the values corresponding to the key.

Return type:

Series

Lookup

arkouda.Series.locate(self, key)

Lookup values by index label.

Parameters:

key (Union[int, pdarray, Index, Series, List, Tuple]) –

The key or keys to look up. This can be: - A scalar - A list of scalars - A list of lists (for MultiIndex) - A Series (in which case labels are preserved, and its values are used as keys)

Keys will be converted to Arkouda arrays as needed.

Returns:

A Series containing the values corresponding to the key.

Return type:

Series

Sorting

arkouda.Series.sort_index(self, ascending=True)

Sort the Series by its index.

Parameters:

ascending (bool) – Whether to sort the index in ascending (default) or descending order. Defaults to True.

Returns:

A new Series sorted by index.

Return type:

Series

arkouda.Series.sort_values(self, ascending=True)

Sort the Series by its values.

Parameters:

ascending (bool) – Whether to sort values in ascending (default) or descending order. Defaults to True.

Returns:

A new Series sorted by its values.

Return type:

Series

Head/Tail

arkouda.Series.topn(self, n=10)

Return the top values of the Series.

Parameters:

n (int) – Number of values to return. Defaults to 10.

Returns:

A new Series containing the top n values.

Return type:

Series

arkouda.Series.head(self, n=10)

Return the first n values of the series.

Return type:

Series

arkouda.Series.tail(self, n=10)

Return the last n values of the series.

Return type:

Series

Value Counts

arkouda.Series.value_counts(self, sort=True)

Return a Series containing counts of unique values.

Parameters:

sort (bool) – Whether to sort the result by count in descending order. If False, the order of the results is not guaranteed. Defaults to True.

Returns:

A Series where the index contains the unique values and the values are their counts in the original Series.

Return type:

Series

Pandas Integration

arkouda.Series.to_pandas(self)

Convert the series to a local PANDAS series.

Return type:

Series

arkouda.Series.pdconcat(arrays, axis=0, labels=None)

Concatenate a list of Arkouda Series or grouped arrays, returning a local pandas object.

If a list of grouped Arkouda arrays is passed, they are converted to Series. Each grouping is a 2-tuple with the first item being the key(s) and the second the value.

If axis=1 (horizontal), each Series or grouping must have the same length and the same index. The index is converted to a column in the resulting DataFrame. If it is a MultiIndex, each level is converted to a separate column.

Parameters:

• arrays (List) – A list of Series or groupings (tuples of index and values) to concatenate.

• axis (int) – The axis along which to concatenate: - 0 = vertical (stack into a Series) - 1 = horizontal (align by index into a DataFrame) Defaults to 0.

• labels (Optional[Strings]) – Names to assign to the resulting columns in the DataFrame.

Returns:

• If axis=0: a local pandas Series

• If axis=1: a local pandas DataFrame

Return type:

Union[Series, DataFrame]