Other examples would be validation/filtering of the set attributes (forcing them to be in bounds or acceptable) and lazy evaluation of complex or rapidly changing terms.
Complex calculation hidden behind an attribute:
class PDB_Calculator(object):
...
@property
def protein_folding_angle(self):
# number crunching, remote server calls, etc
# all results in an angle set in 'some_angle'
# It could also reference a cache, remote or otherwise,
# that holds the latest value for this angle
return some_angle
>>> f = PDB_Calculator()
>>> angle = f.protein_folding_angle
>>> angle
44.33276
Validation:
class Pedometer(object)
...
@property
def stride_length(self):
return self._stride_length
@stride_length.setter
def stride_length(self, value):
if value > 10:
raise ValueError("This pedometer is based on the human stride - a stride length above 10m is not supported")
else:
self._stride_length = value