DOC add missing versionadded marker in docstring
@@ -115,6 +115,9 @@ class SimpleImputer(BaseEstimator, TransformerMixin):
- If "constant", then replace missing values with fill_value. Can be
used with strings or numeric data.
+ .. versionadded:: 0.20
+ strategy="constant" for fixed value imputation.
+
fill_value : string or numerical value, optional
When strategy == "constant", fill_value is used to replace all
occurrences of missing_values.
