diff --git a/python/fbprophet/diagnostics.py b/python/fbprophet/diagnostics.py
index 6e83a7c..7b4a5b3 100644
--- a/python/fbprophet/diagnostics.py
+++ b/python/fbprophet/diagnostics.py
@@ -131,12 +131,13 @@ def cross_validation(model, horizon, period=None, initial=None, parallel=None, c
     if cutoffs is None:
         # Set period
         period = 0.5 * horizon if period is None else pd.Timedelta(period)
-        
+
         # Set initial
-        if initial is None:
-            initial = max(3 * horizon, seasonality_dt)
-        else:
-            initial = pd.Timedelta(initial)
+        initial = (
+            max(3 * horizon, seasonality_dt) if initial is None
+            else pd.Timedelta(initial)
+        )
+
         # Compute Cutoffs
         cutoffs = generate_cutoffs(df, horizon, initial, period)
     else: