Support encoding/decoding of unicode strings between the API and the core

1 files changed, 90 insertions, 0 deletions

diff --git a/python/compatibility.py b/python/compatibility.py
new file mode 100644
index 00000000..0a40328a
--- /dev/null
+++ b/python/compatibility.py
@@ -0,0 +1,90 @@
+# Copyright (c) 2015-2019 Vector 35 Inc
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to
+# deal in the Software without restriction, including without limitation the
+# rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+# sell copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in
+# all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+# FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+# IN THE SOFTWARE.
+
+# 2-3 compatibility
+import sys
+
+PY2 = sys.version_info[0] == 2
+PY3 = sys.version_info[0] == 3
+PY34 = sys.version_info[0:2] >= (3, 4)
+
+
+if PY2:
+  def range(*args):
+    return xrange(*args)
+
+  def valid_import(mod_name):
+    import imp
+    try:
+      imp.find_module(mod_name)
+      found = True
+    except ImportError:
+      found = False
+    return found
+
+  def pyNativeStr(arg):
+    return arg
+
+
+if PY3:
+  range = range  # Range needs to explicitly be defined or it's an error
+
+  def valid_import(mod_name):
+    import importlib
+    mod_loader = importlib.find_loader(mod_name)
+    found = mod_loader is not None
+    return found
+
+  def pyNativeStr(arg):
+    if isinstance(arg, str):
+      return arg
+    else:
+      try:
+        return arg.decode('utf8')
+      except UnicodeDecodeError:
+        return arg.decode('charmap')
+
+
+if PY34:
+  def valid_import(mod_name):
+    import importlib.util
+    return importlib.util.find_spec(mod_name) is not None
+
+
+def with_metaclass(meta, *bases):
+  """Create a base class with a metaclass."""
+  class metaclass(type):
+    def __new__(cls, name, this_bases, d):
+      return meta(name, bases, d)
+
+    @classmethod
+    def __prepare__(cls, name, this_bases):
+      return meta.__prepare__(name, bases)
+  return type.__new__(metaclass, 'temporary_class', (), {})
+
+
+def cstr(arg):
+  if isinstance(arg, bytes) or arg is None:
+    return arg
+  else:
+    try:
+      return arg.encode('charmap')
+    except UnicodeEncodeError:
+      return arg.encode('utf8')