I have the following example.py
file:
class Location(object):
def __init__(self, latitude, longitude):
self.latitude = latitude
self.longitude = longitude
@property
def latitude(self):
return self._latitude
@property
def longitude(self):
return self._longitude
@latitude.setter
def latitude(self, latitude):
"""Setter for latiutde."""
if not (-90 <= latitude <= 90):
raise ValueError('latitude was {}, but has to be in [-90, 90]'
.format(latitude))
self._latitude = latitude
@longitude.setter
def longitude(self, longitude):
"""Setter for longitude."""
if not (-180 <= longitude <= 180):
raise ValueError('longitude was {}, but has to be in [-180, 180]'
.format(longitude))
self._longitude = longitude
def __repr__(self):
return 'Location({}, {})'.format(self.latitude, self.longitude)
__str__ = __repr__
munich = Location(48.137222222222, 11.57555)
print(munich)
try:
munich.latitude = 200
print("This should not work")
except ValueError:
pass
When I run mypy example.py
(mypy version 0.73) I get a couple of errors:
$ mypy example.py
example.py:14: error: Name 'latitude' already defined on line 6
example.py:14: error: "Callable[[Any], Any]" has no attribute "setter"
example.py:22: error: Name 'longitude' already defined on line 10
example.py:22: error: "Callable[[Any], Any]" has no attribute "setter"
example.py:39: error: Property "latitude" defined in "Location" is read-only
Found 5 errors in 1 file (checked 1 source file)
Why do I get those and how can I fix it?
The issue is probably related to Property setter not accepted if not next to getter.
The following code incorrectly raises an error:
class Config(object): @property def my_proprty(self): return None def _other(self): pass @my_proprty.setter def my_proprty(self, val): pass Error:
mypytest.py: note: In class "Config": mypytest.py:12: error: Callable[[Any], Any] has no attribute "setter"
MyPy closed the issue and marked it as a false-positive. It appears they have no intentions of fixing it as of now.
We don't have immediate plans for fix this issue, but we are happy to receive a PR. - JukkaL
Moving your getters and setters next to each other (with the getter first) should fix the issue.
Consider it a feature :)