Import dowhy.causal_estimators.econml locally (#713)

This imports it within the function where it's used. It removes the hard dependency on EconML and only requires it when using sensitivity_non_parametric_partial_r2.

Signed-off-by: Peter Goetz <pego@amazon.com>

Signed-off-by: Peter Goetz <pego@amazon.com>

dowhy/causal_refuters/add_unobserved_common_cause.py

@@ -11,7 +11,6 @@ from sklearn.linear_model import LogisticRegression
 from sklearn.preprocessing import StandardScaler
 from tqdm.auto import tqdm
 
-import dowhy.causal_estimators.econml
 from dowhy.causal_estimator import CausalEstimate, CausalEstimator
 from dowhy.causal_estimators.linear_regression_estimator import LinearRegressionEstimator
 from dowhy.causal_estimators.regression_estimator import RegressionEstimator
@@ -672,6 +671,8 @@ def sensitivity_non_parametric_partial_r2(
     :plugin_reisz: bool: Flag on whether to use the plugin estimator or the nonparametric estimator for reisz representer function (alpha_s).
     """
 
+    import dowhy.causal_estimators.econml
+
     # If the estimator used is LinearDML, partially linear sensitivity analysis will be automatically chosen
     if isinstance(estimate.estimator, dowhy.causal_estimators.econml.Econml):
         if estimate.estimator._econml_methodname == "econml.dml.LinearDML":