diff --git a/.gitignore b/.gitignore
index 603dc16..92c5123 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,4 +1,29 @@
-.idea
+# Python
 __pycache__/
+*.py[cod]
+
+# Virtual environments
+.venv/
+venv/
+
+# Packaging / build artifacts
+*.egg-info/
+build/
+dist/
+
+# Testing and coverage
+.pytest_cache/
+.coverage
+.coverage.*
+htmlcov/
+coverage.xml
+
+# Jupyter
 .ipynb_checkpoints
+
+# Editors / IDEs
+.idea/
+.vscode/
+
+# Project specific
 backup/
diff --git a/sensemakr/sensitivity_plots.py b/sensemakr/sensitivity_plots.py
index 51890f5..ee2f9fd 100644
--- a/sensemakr/sensitivity_plots.py
+++ b/sensemakr/sensitivity_plots.py
@@ -624,7 +624,7 @@ def extract_from_model(model, treatment, benchmark_covariates, kd, ky, r2dz_x, r
     se = model_data['se']
     dof = model_data['dof']
     try:
-        estimate, se = float(estimate), float(se)
+        estimate, se = float(estimate.iloc[0]), float(se.iloc[0])
     except:
         sys.exit('Error: The estimated effect and standard error must be numeric.')
 
diff --git a/sensemakr/sensitivity_statistics.py b/sensemakr/sensitivity_statistics.py
index 1551680..0d2f057 100644
--- a/sensemakr/sensitivity_statistics.py
+++ b/sensemakr/sensitivity_statistics.py
@@ -174,7 +174,7 @@ def partial_r2(model=None, covariates=None, t_statistic=None, dof=None):
         model_data = model_helper(model, covariates=covariates)
         t_statistic = model_data['t_statistics']
         dof = model_data['dof']
-        return (t_statistic ** 2 / (t_statistic ** 2 + dof))[0]  # extracts float
+        return (t_statistic ** 2 / (t_statistic ** 2 + dof)).iloc[0]  # extracts float
     else:
         return t_statistic ** 2 / (t_statistic ** 2 + dof)