add pt2tf tool

pt2tf/onnx-tensorflow/onnx_tf/common/legacy.py

@@ -0,0 +1,21 @@
+from __future__ import absolute_import
+from __future__ import division
+from __future__ import print_function
+from __future__ import unicode_literals
+
+import onnx
+
+
+def get_onnx_version():
+  return tuple(map(int, onnx.version.version.split(".")))
+
+
+# Returns whether onnx version is prior to major.minor.patch
+def legacy_onnx_pre_ver(major=0, minor=0, patch=0):
+  return get_onnx_version() < (major, minor, patch)
+
+
+# Returns whether the opset version accompanying the
+# onnx installation is prior to version passed.
+def legacy_opset_pre_ver(version):
+  return onnx.defs.onnx_opset_version() < version