Fix Python version compatibility issue with previous commit.
diff --git a/generator/nanopb_generator.py b/generator/nanopb_generator.py
index b04135e..601c0b6 100755
--- a/generator/nanopb_generator.py
+++ b/generator/nanopb_generator.py
@@ -10,6 +10,7 @@
import re
import codecs
import copy
+import itertools
import tempfile
import shutil
import os
@@ -992,7 +993,7 @@
# submessages.
union_name = "%s_%s_size_union" % (self.struct_name, self.name)
union_def = 'union %s {%s};\n' % (union_name, ' '.join('char f%d[%s];' % (k, s) for k,s in dynamic_sizes.items()))
- required_defs = sum([s.required_defines for k,s in dynamic_sizes.items()], start = [])
+ required_defs = list(itertools.chain.from_iterable(s.required_defines for k,s in dynamic_sizes.items()))
return EncodedSize(0, ['sizeof(%s)' % union_name], [union_def], required_defs)
def has_callbacks(self):
