Why does model.save(path) fail with path an openstudio.path()?

asked 2024-03-29 13:44:01 -0500

mattkoch
997 ●10 ●8

updated 2024-03-29 13:44:48 -0500

I just upgraded from openstudio-3.6.0 SDK to opnstudio-3.7.0 SDK in Python. The following simple test used to work in 3.6.0:

import openstudio
model = openstudio.model.Model()
path = openstudio.path("./ModelTest.osm")
model.save(path)

However, in 3.7.0, I receive the following error:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "D:\Python-3.10.11\lib\site-packages\openstudio\openstudioutilitiesidf.py", line 1997, in save
    return _openstudioutilitiesidf.Workspace_save(self, p, overwrite)
TypeError: Wrong number or type of arguments for overloaded function 'Workspace_save'.
  Possible C/C++ prototypes are:
    openstudio::Workspace::save(openstudio::path const &,bool)
    openstudio::Workspace::save(openstudio::path const &)

Interestingly, the following does seem to work instead, namely using a simple Python String instead of an OpenStudio Path:

import openstudio
model = openstudio.model.Model()
path = "./ModelTest.osm"
model.save(path)

Is there some type incompatibility going on? A "pip freeze" does confirm that I am using openstudio-3.7.0 in my Python-3.10.11.

answered 2024-03-29 14:14:22 -0500

Julien Marrec

29112 ●87 ●74 http://www.effibem.com/

updated 2024-03-29 14:18:10 -0500

Sorry for the trouble, I added a conversion to/from openstudio.Path to python's pathlib.Path, and apprently messed something up.

Basically this comes from (an honestly good) intention, which was to allow seemless conversion to/from pathlib.Path but it seems it does have the side effect that it rejects an openstudio.Path now.

You might have noticed that anything returning an openstudio::path now converts to a pathlib.Path

In [1]: osw = openstudio.WorkflowJSON()

In [2]: osw.absoluteRootDir()
Out[2]: PosixPath('......')

Similarly you can pass a pathlib.Path to something taking an openstudio::Path. Or a string.

In [1]: from pathlib import Path
        import openstudio
        m = openstudio.model.Model()

 In [5]: m.save('model.osm', True)
 Out[5]: True

 In [6]: m.save(Path('model.osm'), True)
 Out[6]: True

Bottom line, use a python string or a pathtlib.Path. Use str(the_path) if you don't know what you're getting in.

I filed it at NREL/OpenStudio#5133

Please note that such changes may be unexpected (I mean such as returning a pathlib.Path, not breaking existing workflows), but support for Python Measures was not effective before so it was a more than appropriate time to perform usability-related API breaks before we got stuck with the status quo.

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Comments

No problem, Julien Marrec. If you are the driving force behind the Python port of openstudio, then the world owes you a huge debt of gratitude no matter what you do with openstudio.path. Being able to work in Python and make use of its near-infinite universe is such a relief! Python is such a natural language that it speeds up my work by a factor two to three compared to Ruby! Oh, and by the way, os.path also works on both model.load() and model.save().