larray.from_frame¶

larray.from_frame(df, sort_rows=False, sort_columns=False, parse_header=False, unfold_last_axis_name=False, fill_value=nan, meta=None, cartesian_prod=True, **kwargs) → larray.core.array.Array[source]¶

Converts Pandas DataFrame into Array.

Parameters:

df : pandas.DataFrame: Input dataframe. By default, name and labels of the last axis are defined by the name and labels of the columns Index of the dataframe unless argument unfold_last_axis_name is set to True.
sort_rows : bool, optional: Whether to sort the rows alphabetically (sorting is more efficient than not sorting). Must be False if cartesian_prod is set to True. Defaults to False.
sort_columns : bool, optional: Whether to sort the columns alphabetically (sorting is more efficient than not sorting). Must be False if cartesian_prod is set to True. Defaults to False.
parse_header : bool, optional: Whether to parse columns labels. Pandas treats column labels as strings. If True, column labels are converted into int, float or boolean when possible. Defaults to False.
unfold_last_axis_name : bool, optional: Whether to extract the names of the last two axes by splitting the name of the last index column of the dataframe using \. Defaults to False.
fill_value : scalar, optional: Value used to fill cells corresponding to label combinations which are not present in the input DataFrame. Defaults to NaN.
meta : list of pairs or dict or Metadata, optional: Metadata (title, description, author, creation_date, …) associated with the array. Keys must be strings. Values must be of type string, int, float, date, time or datetime.
cartesian_prod : bool, optional: Whether to expand the dataframe to a cartesian product dataframe as needed by Array. This is an expensive operation but is absolutely required if you cannot guarantee your dataframe is already well formed. If True, arguments sort_rows and sort_columns must be set to False. Defaults to True.

Returns:

Array

See also

Array.to_frame

Examples

>>> from larray import ndtest
>>> df = ndtest((2, 2, 2)).to_frame()
>>> df                                                                             # doctest: +NORMALIZE_WHITESPACE
c      c0  c1
a  b
a0 b0   0   1
   b1   2   3
a1 b0   4   5
   b1   6   7
>>> from_frame(df)
 a  b\c  c0  c1
a0   b0   0   1
a0   b1   2   3
a1   b0   4   5
a1   b1   6   7

Names of the last two axes written as before_last_axis_name\\last_axis_name

>>> df = ndtest((2, 2, 2)).to_frame(fold_last_axis_name=True)
>>> df                                                                             # doctest: +NORMALIZE_WHITESPACE
        c0  c1
a  b\c
a0 b0    0   1
   b1    2   3
a1 b0    4   5
   b1    6   7
>>> from_frame(df, unfold_last_axis_name=True)
 a  b\c  c0  c1
a0   b0   0   1
a0   b1   2   3
a1   b0   4   5
a1   b1   6   7