orange3: ImportError: kann Name '_variable' nicht importieren

Question

Ich versuche, Orange3 auf meinem Mac zu verwenden, aber ich erhalte diesen Fehler: ImportError: cannot import name '_variable'.

Dies ist mein Setup:

$ cd orange_playground 
$ virtualenv -p python3 venv 
$ pip install orange3 
$ source venv/bin/activate 
$ python 

Die Ausgabe ist wie folgt:

Python 3.4.2 (default, Oct 8 2014, 19:29:52) 
[GCC 4.2.1 Compatible Apple LLVM 6.0 (clang-600.0.51)] on darwin 
Type "help", "copyright", "credits" or "license" for more information. 
>>> import Orange 
Traceback (most recent call last): 
    File "<stdin>", line 1, in <module> 
    File "orange_playground/venv/lib/python3.4/site-packages/Orange/__init__.py", line 11, in <module> 
    from .misc.lazy_module import _LazyModule 
    File "orange_playground/venv/lib/python3.4/site-packages/Orange/misc/__init__.py", line 3, in <module> 
    from .distmatrix import DistMatrix 
    File "orange_playground/venv/lib/python3.4/site-packages/Orange/misc/distmatrix.py", line 3, in <module> 
    from Orange.data import Table, StringVariable, Domain 
    File "orange_playground/venv/lib/python3.4/site-packages/Orange/data/__init__.py", line 4, in <module> 
    from .variable import * 
    File "orange_playground/venv/lib/python3.4/site-packages/Orange/data/variable.py", line 11, in <module> 
    from Orange.data import _variable 
ImportError: cannot import name '_variable' 

Erste Zeilen Code aus orange_playground/venv/lib/python3.4/site-packages/Orange/data/variable.py:

import collections 
import re 

from datetime import datetime, timedelta, timezone 
from numbers import Number, Real, Integral 
from math import isnan, floor 
from pickle import PickleError 

import numpy as np 

from Orange.data import _variable 
from Orange.util import Registry, color_to_hex, hex_to_color 

__all__ = ["Unknown", "MISSING_VALUES", "make_variable", "is_discrete_values", 
      "Value", "Variable", "ContinuousVariable", "DiscreteVariable", 
      "StringVariable", "TimeVariable"] 


# For storing unknowns 
Unknown = ValueUnknown = float("nan") 
# For checking for unknowns 
MISSING_VALUES = {np.nan, "?", "nan", ".", "", "NA", "~", None} 

... 

Irgendwelche Ideen, was zu tun?

Answer 1

Installing Orange3 from source wie @MartijnPieters vorgeschlagen funktioniert! Vielen Dank.