take docstrings outside discretiser base class

feature_engine/_docstrings/fit_attributes.py

@@ -11,3 +11,7 @@
 _n_features_in_docstring = """n_features_in_:
         The number of features in the train set used in fit.
         """.rstrip()
+
+_binner_dict_docstring = """binner_dict_:
+         Dictionary with the interval limits per variable.
+     """.rstrip()

feature_engine/_docstrings/init_parameters/discretisers.py

@@ -0,0 +1,10 @@
+_return_object_docstring = """return_object: bool, default=False
+        Whether the the discrete variable should be returned as type numeric or type
+        object. If you would like to encode the discrete variables with Feature-engine's
+        categorical encoders, use True. Alternatively, keep the default to False.
+    """.rstrip()
+
+_return_boundaries_docstring = """return_boundaries: bool, default=False
+        Whether the output should be the interval boundaries. If True, it returns
+        the interval boundaries. If False, it returns integers.
+    """.rstrip()

feature_engine/_docstrings/methods.py

@@ -31,3 +31,12 @@
 _transform_creation_docstring = """transform:
         Create new features.
     """.rstrip()
+
+# used in discretisers module
+_fit_discretiser_docstring = """fit:
+        Find the interval limits.
+    """.rstrip()
+
+_transform_discretiser_docstring = """transform:
+        Sort continuous variable values into the intervals.
+    """.rstrip()

feature_engine/discretisation/arbitrary.py

@@ -10,22 +10,27 @@
 from feature_engine._docstrings.fit_attributes import (
     _feature_names_in_docstring,
     _n_features_in_docstring,
-    _variables_attribute_docstring,
+    _variables_attribute_docstring, _binner_dict_docstring,
+)
+from feature_engine._docstrings.init_parameters.discretisers import (
+    _return_object_docstring,
+    _return_boundaries_docstring,
 )
 from feature_engine._docstrings.methods import (
     _fit_not_learn_docstring,
     _fit_transform_docstring,
+    _transform_discretiser_docstring,
 )
 from feature_engine._docstrings.substitute import Substitution
 from feature_engine.discretisation.base_discretiser import BaseDiscretiser
 from feature_engine.tags import _return_tags
 
 
 @Substitution(
-    return_object=BaseDiscretiser._return_object_docstring,
-    return_boundaries=BaseDiscretiser._return_boundaries_docstring,
-    binner_dict_=BaseDiscretiser._binner_dict_docstring,
-    transform=BaseDiscretiser._transform_docstring,
+    return_object=_return_object_docstring,
+    return_boundaries=_return_boundaries_docstring,
+    binner_dict_=_binner_dict_docstring,
+    transform=_transform_discretiser_docstring,
     variables_=_variables_attribute_docstring,
     feature_names_in_=_feature_names_in_docstring,
     n_features_in_=_n_features_in_docstring,

feature_engine/discretisation/base_discretiser.py

@@ -13,29 +13,6 @@ class BaseDiscretiser(BaseNumericalTransformer):
     Important: inherits fit() functionality and tags from BaseNumericalTransformer.
     """
 
-    _return_object_docstring = """return_object: bool, default=False
-        Whether the the discrete variable should be returned as numeric or as
-        object. If you would like to proceed with the engineering of the variable as if
-        it was categorical, use True. Alternatively, keep the default to False.
-        """.rstrip()
-
-    _return_boundaries_docstring = """return_boundaries: bool, default=False
-        Whether the output should be the interval boundaries. If True, it returns
-        the interval boundaries. If False, it returns integers.
-        """.rstrip()
-
-    _binner_dict_docstring = """binner_dict_:
-         Dictionary with the interval limits per variable.
-         """.rstrip()
-
-    _fit_docstring = """fit:
-        Find the interval limits.
-        """.rstrip()
-
-    _transform_docstring = """transform:
-        Sort continuous variable values into the intervals.
-    """
-
     def __init__(
         self,
         return_object: bool = False,

feature_engine/discretisation/equal_frequency.py

@@ -8,12 +8,20 @@
 from feature_engine._docstrings.fit_attributes import (
     _feature_names_in_docstring,
     _n_features_in_docstring,
-    _variables_attribute_docstring,
+    _variables_attribute_docstring, _binner_dict_docstring,
 )
 from feature_engine._docstrings.init_parameters.all_trasnformers import (
     _variables_numerical_docstring,
 )
-from feature_engine._docstrings.methods import _fit_transform_docstring
+from feature_engine._docstrings.init_parameters.discretisers import (
+    _return_object_docstring,
+    _return_boundaries_docstring,
+)
+from feature_engine._docstrings.methods import (
+    _fit_transform_docstring,
+    _fit_discretiser_docstring,
+    _transform_discretiser_docstring,
+)
 from feature_engine._docstrings.substitute import Substitution
 from feature_engine._variable_handling.init_parameter_checks import (
     _check_init_parameter_variables,
@@ -22,11 +30,11 @@
 
 
 @Substitution(
-    return_object=BaseDiscretiser._return_object_docstring,
-    return_boundaries=BaseDiscretiser._return_boundaries_docstring,
-    binner_dict_=BaseDiscretiser._binner_dict_docstring,
-    fit=BaseDiscretiser._fit_docstring,
-    transform=BaseDiscretiser._transform_docstring,
+    return_object=_return_object_docstring,
+    return_boundaries=_return_boundaries_docstring,
+    binner_dict_=_binner_dict_docstring,
+    fit=_fit_discretiser_docstring,
+    transform=_transform_discretiser_docstring,
     variables=_variables_numerical_docstring,
     variables_=_variables_attribute_docstring,
     feature_names_in_=_feature_names_in_docstring,

feature_engine/discretisation/equal_width.py

@@ -8,12 +8,20 @@
 from feature_engine._docstrings.fit_attributes import (
     _feature_names_in_docstring,
     _n_features_in_docstring,
-    _variables_attribute_docstring,
+    _variables_attribute_docstring, _binner_dict_docstring,
 )
 from feature_engine._docstrings.init_parameters.all_trasnformers import (
     _variables_numerical_docstring,
 )
-from feature_engine._docstrings.methods import _fit_transform_docstring
+from feature_engine._docstrings.init_parameters.discretisers import (
+    _return_object_docstring,
+    _return_boundaries_docstring,
+)
+from feature_engine._docstrings.methods import (
+    _fit_transform_docstring,
+    _fit_discretiser_docstring,
+    _transform_discretiser_docstring,
+)
 from feature_engine._docstrings.substitute import Substitution
 from feature_engine._variable_handling.init_parameter_checks import (
     _check_init_parameter_variables,
@@ -22,11 +30,11 @@
 
 
 @Substitution(
-    return_object=BaseDiscretiser._return_object_docstring,
-    return_boundaries=BaseDiscretiser._return_boundaries_docstring,
-    binner_dict_=BaseDiscretiser._binner_dict_docstring,
-    fit=BaseDiscretiser._fit_docstring,
-    transform=BaseDiscretiser._transform_docstring,
+    return_object=_return_object_docstring,
+    return_boundaries=_return_boundaries_docstring,
+    binner_dict_=_binner_dict_docstring,
+    fit=_fit_discretiser_docstring,
+    transform=_transform_discretiser_docstring,
     variables=_variables_numerical_docstring,
     variables_=_variables_attribute_docstring,
     feature_names_in_=_feature_names_in_docstring,