check the protobuf version

x2paddle/convert.py

@@ -122,7 +122,16 @@ def caffe2paddle(proto, weight, save_dir, caffe_proto):
     from x2paddle.decoder.caffe_decoder import CaffeDecoder
     from x2paddle.op_mapper.caffe_op_mapper import CaffeOpMapper
     from x2paddle.optimizer.caffe_optimizer import CaffeOptimizer
-
+    s = sys.version
+    if s.startswith('2'):
+        import commands
+        pb_version = commands.getstatusoutput('protoc --version')[1]
+    else:
+        import subprocess
+        pb_version = subprocess.getstatusoutput('protoc --version')[1]
+    ver_str = pb_version.split(' ')[-1].replace('.', '')
+    ver_int = int(ver_str)
+    assert ver_int >= 360, 'The version of protobuf must be larger than 3.6.0!'
     print("Now translating model from caffe to paddle.")
     model = CaffeDecoder(proto, weight, caffe_proto)
     mapper = CaffeOpMapper(model)