Update types.py

Author: maver1ck

python/pyspark/sql/types.py

@@ -483,7 +483,8 @@ def __init__(self, fields=None):
             self.names = [f.name for f in fields]
             assert all(isinstance(f, StructField) for f in fields),\
                 "fields should be a list of StructField"
-        self._needSerializeAnyField = any(f.needConversion() for f in self)
+        self._needConversion = [f.needConversion() for f in self]
+        self._needSerializeAnyField = any(self._needConversion)
 
     def add(self, field, data_type=None, nullable=True, metadata=None):
         """
@@ -528,7 +529,8 @@ def add(self, field, data_type=None, nullable=True, metadata=None):
                 data_type_f = data_type
             self.fields.append(StructField(field, data_type_f, nullable, metadata))
             self.names.append(field)
-        self._needSerializeAnyField = any(f.needConversion() for f in self)
+        self._needConversion = [f.needConversion() for f in self]
+        self._needSerializeAnyField = any(self._needConversion)
         return self
 
     def __iter__(self):
@@ -619,7 +621,7 @@ def fromInternal(self, obj):
             # it's already converted by pickler
             return obj
         if self._needSerializeAnyField:
-            values = [f.fromInternal(v) for f, v in zip(self.fields, obj)]
+            values = [f.fromInternal(v) if n else v for f, v, n in zip(self.fields, obj, self._needConversion)]
         else:
             values = obj
         return _create_row(self.names, values)