JSON schema files are not found on a mapped network drive under Windows 10

[peterschaer]

In our environment (Windows 10), mappyfile is installed on a mapped network drive. In this case mappyfile cannot find its schema files (*.json) in the schemas subdirectory. The following error message is displayed:

>>> import mappyfile
>>> mapfile = mappyfile.open(r"C:\ProgramData\OEREBK\oerebpruef\oerebpruef\oerebpruef_gemeinde.map")
>>> mappyfile.dumps(mapfile)
Traceback (most recent call last):
  File "C:\Program Files\ArcGIS\Pro\bin\Python\envs\arcgispro-py3\lib\urllib\request.py", line 1503, in open_local_file
    stats = os.stat(localfile)
FileNotFoundError: [WinError 3] Das System kann den angegebenen Pfad nicht finden: '\\a2za-cfs-data0.jgk.be.ch\\data0\\GIS02\\Anwend\\Tools\\Python_Module\\Python_Installation\\Python39\\site-packages\\mappyfile\\schemas\\onoff.json'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "K:\Anwend\Tools\Python_Module\Python_Installation\Python39\site-packages\jsonref.py", line 130, in callback
    base_doc = self.loader(uri)
  File "K:\Anwend\Tools\Python_Module\Python_Installation\Python39\site-packages\jsonref.py", line 255, in jsonloader
    with urlopen(uri) as content:
  File "C:\Program Files\ArcGIS\Pro\bin\Python\envs\arcgispro-py3\lib\urllib\request.py", line 214, in urlopen
    return opener.open(url, data, timeout)
  File "C:\Program Files\ArcGIS\Pro\bin\Python\envs\arcgispro-py3\lib\urllib\request.py", line 517, in open
    response = self._open(req, data)
  File "C:\Program Files\ArcGIS\Pro\bin\Python\envs\arcgispro-py3\lib\urllib\request.py", line 534, in _open
    result = self._call_chain(self.handle_open, protocol, protocol +
  File "C:\Program Files\ArcGIS\Pro\bin\Python\envs\arcgispro-py3\lib\urllib\request.py", line 494, in _call_chain
    result = func(*args)
  File "C:\Program Files\ArcGIS\Pro\bin\Python\envs\arcgispro-py3\lib\urllib\request.py", line 1481, in file_open
    return self.open_local_file(req)
  File "C:\Program Files\ArcGIS\Pro\bin\Python\envs\arcgispro-py3\lib\urllib\request.py", line 1520, in open_local_file
    raise URLError(exp)
urllib.error.URLError: <urlopen error [WinError 3] Das System kann den angegebenen Pfad nicht finden: '\\a2za-cfs-data0.jgk.be.ch\\data0\\GIS02\\Anwend\\Tools\\Python_Module\\Python_Installation\\Python39\\site-packages\\mappyfile\\schemas\\onoff.json'>

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "K:\Anwend\Tools\Python_Module\Python_Installation\Python39\site-packages\mappyfile\utils.py", line 414, in dumps
    return _pprint(
  File "K:\Anwend\Tools\Python_Module\Python_Installation\Python39\site-packages\mappyfile\utils.py", line 478, in _pprint
    return pp.pprint(d)
  File "K:\Anwend\Tools\Python_Module\Python_Installation\Python39\site-packages\mappyfile\pprint.py", line 330, in pprint
    lines += self._format(composite)
  File "K:\Anwend\Tools\Python_Module\Python_Installation\Python39\site-packages\mappyfile\pprint.py", line 565, in _format
    line = self.process_attribute(
  File "K:\Anwend\Tools\Python_Module\Python_Installation\Python39\site-packages\mappyfile\pprint.py", line 455, in process_attribute
    value = self.format_value(attr, attr_props, value)
  File "K:\Anwend\Tools\Python_Module\Python_Installation\Python39\site-packages\mappyfile\pprint.py", line 379, in format_value
    if any(i in ["enum"] for i in attr_props):
  File "K:\Anwend\Tools\Python_Module\Python_Installation\Python39\site-packages\proxytypes.py", line 189, in proxied
    args.insert(arg_pos, self.__subject__)
  File "K:\Anwend\Tools\Python_Module\Python_Installation\Python39\site-packages\proxytypes.py", line 163, in __getattribute__
    return _oga(self, attr)
  File "K:\Anwend\Tools\Python_Module\Python_Installation\Python39\site-packages\proxytypes.py", line 121, in wrapper
    return method(self, *args, **kwargs)
  File "K:\Anwend\Tools\Python_Module\Python_Installation\Python39\site-packages\proxytypes.py", line 243, in __subject__
    self.cache = super(LazyProxy, self).__subject__
  File "K:\Anwend\Tools\Python_Module\Python_Installation\Python39\site-packages\proxytypes.py", line 121, in wrapper
    return method(self, *args, **kwargs)
  File "K:\Anwend\Tools\Python_Module\Python_Installation\Python39\site-packages\proxytypes.py", line 227, in __subject__
    return self.callback()
  File "K:\Anwend\Tools\Python_Module\Python_Installation\Python39\site-packages\proxytypes.py", line 121, in wrapper
    return method(self, *args, **kwargs)
  File "K:\Anwend\Tools\Python_Module\Python_Installation\Python39\site-packages\jsonref.py", line 132, in callback
    raise self._error(
jsonref.JsonRefError: Error while resolving `file:///a2za-cfs-data0.jgk.be.ch/data0/GIS02/Anwend/Tools/Python_Module/Python_Installation/Python39/site-packages/mappyfile/schemas/onoff.json`: URLError: <urlopen error [WinError 3] Das System kann den angegebenen Pfad nicht finden: '\\a2za-cfs-data0.jgk.be.ch\\data0\\GIS02\\Anwend\\Tools\\Python_Module\\Python_Installation\\Python39\\site-packages\\mappyfile\\schemas\\onoff.json'>

If mappyfile is installed on a local drive (e.g. C:), the schema files can be found.

As a workaround, I have removed the call to os.path.realpath() in line 71 in validator.py.

mappyfile/mappyfile/validator.py

Line 71 in dadca20

return os.path.join(os.path.dirname(os.path.realpath(__file__)), "schemas")

The schema files are then found.

Environment:
Python 3.9.16
mappyfile 1.0.1
jsonref 1.1.0
jsonschema 4.22.0

[geographika]

@peterschaer - thanks for reporting. Now mappyfile is Python3 only this can probably be rewritten to use a path from the package resources.
In your example above what do the two different calls return?

# current / broken
print(os.path.join(os.path.dirname(os.path.realpath(__file__)), "schemas"))
# patched / working
print(os.path.join(os.path.dirname(__file__), "schemas"))

[peterschaer]

Here are my return values:

print(os.path.join(os.path.dirname(os.path.realpath(__file__)), "schemas"))
\\a2za-cfs-data0.jgk.be.ch\data0\GIS02\Anwend\Tools\Python_Module\Python_Installation\Python39\site-packages\mappyfile\schemas

print(os.path.join(os.path.dirname(__file__), "schemas"))
K:\Anwend\Tools\Python_Module\Python_Installation\Python39\site-packages\mappyfile\schemas

[geographika]

Interesting. Looks like realpath was updated to get the real path behind Windows network drive mappings in https://bugs.python.org/issue36112