# Copyright 2022 The SQLNet Company GmbH
#
# This file is licensed under the Elastic License 2.0 (ELv2).
# Refer to the LICENSE.txt file in the root of the repository
# for details.
#
"""
Dataclass for handling the roles.
"""
from dataclasses import dataclass, field, fields
from inspect import cleandoc
from typing import List
[docs]@dataclass
class Roles:
"""
Roles can be passed to :class:`~getml.DataFrame` to
predefine the roles assigned to certain columns.
Example:
>>> roles = getml.data.Roles(
>>> ... categorical=["col1", "col2"], target=["col3"])
>>>
>>> df_expd = data.DataFrame.from_csv(
... fnames=["file1.csv", "file2.csv"],
... name="MY DATA FRAME",
... sep=';',
... quotechar='"',
... roles=roles
... )
"""
categorical: List[str] = field(default_factory=list)
join_key: List[str] = field(default_factory=list)
numerical: List[str] = field(default_factory=list)
target: List[str] = field(default_factory=list)
text: List[str] = field(default_factory=list)
time_stamp: List[str] = field(default_factory=list)
unused_float: List[str] = field(default_factory=list)
unused_string: List[str] = field(default_factory=list)
def __getitem__(self, key):
try:
return getattr(self, key)
except TypeError:
raise KeyError(key)
def __iter__(self):
yield from (field_.name for field_ in fields(self))
def __len__(self):
return len(fields(self))
def __repr__(self):
template = cleandoc(
"""
{role}:
- {cols}
"""
)
blocks = []
for role in self:
if self[role]:
cols = "\n- ".join(self[role])
blocks.append(template.format(role=role, cols=cols))
return "\n\n".join(blocks)
@property
def columns(self):
"""
The name of all columns contained in the roles object.
"""
return [r for role in self for r in self[role]]
[docs] def infer(self, colname):
"""
Infers the role of a column.
Args:
colname (str):
The name of the column to be inferred.
"""
for role in self:
if colname in self[role]:
return role
raise ValueError("Column named '" + colname + "' not found.")
[docs] def to_dict(self):
"""
Expresses the roles object as a dictionary.
"""
return {role: self[role] for role in self}
[docs] def to_list(self):
"""
Returns a list containing the roles, without the corresponding
columns names.
"""
return [r for role in self for r in [role] * len(self[role])]
@property
def unused(self):
"""
Names of all unused columns (unused_float + unused_string).
"""
return self.unused_float + self.unused_string