pyqtgraph/flowchart/eq.py
2012-09-13 11:07:29 -04:00

37 lines
1.1 KiB
Python

# -*- coding: utf-8 -*-
from numpy import ndarray, bool_
from pyqtgraph.metaarray import MetaArray
def eq(a, b):
"""The great missing equivalence function: Guaranteed evaluation to a single bool value."""
if a is b:
return True
try:
e = a==b
except ValueError:
return False
except AttributeError:
return False
except:
print("a:", str(type(a)), str(a))
print("b:", str(type(b)), str(b))
raise
t = type(e)
if t is bool:
return e
elif t is bool_:
return bool(e)
elif isinstance(e, ndarray) or (hasattr(e, 'implements') and e.implements('MetaArray')):
try: ## disaster: if a is an empty array and b is not, then e.all() is True
if a.shape != b.shape:
return False
except:
return False
if (hasattr(e, 'implements') and e.implements('MetaArray')):
return e.asarray().all()
else:
return e.all()
else:
raise Exception("== operator returned type %s" % str(type(e)))