BUG: handle empty lists in json_normalize

xref: pandas-dev#15534

Author: rgbkrk

pandas/io/json/normalize.py

@@ -157,6 +157,9 @@ def _pull_field(js, spec):
 
         return result
 
+    if isinstance(data, list) and len(data) is 0:
+        return DataFrame()
+
     # A bit of a hackjob
     if isinstance(data, dict):
         data = [data]