How to override or perform min/max in python on your own class?
-1
Not sure the best way to title this question, but how can I override or perform min(a, b) or max(a, b) on objects of a class i made? I can override the gt and lt like below but I would like to override the min or max so that I'll be able to use something like max(a, b, c ,d). The class will have multiple property as well, but I think 2 for this example is sufficient.
class MyClass:
def __init__(self, item1, item2):
self.item1 = item1
self.item2 = item2
def __gt__(self, other):
if isinstance(other, MyClass):
if self.item1 > other.item1:
return True
elif self.item1 <= other.item1:
return False
elif self.item2 > other.item2:
return True
elif self.item2 <= other.item2:
return False
def __lt__(self, other):
if isinstance(other, MyClass):
if self.item1 < other.item1:
return True
elif self.item1 >= other.item1:
return False
elif self.item2 < other.item2:
return True
elif self.item2 >= other.item2:
return False
Ex:
a = MyClass(2,3)
b = MyClass(3,3)
print(a > b)
# False
I tried overriding __cmp__ but that doesnt seem to work.
Would like to be able to do max(a, b) and return b object
python max min
edited Nov 14 '18 at 3:29
Aqueous Carlos
301313
asked Nov 14 '18 at 3:24
user1179317user1179317
607818
|
show 3 more comments
-1
Not sure the best way to title this question, but how can I override or perform min(a, b) or max(a, b) on objects of a class i made? I can override the gt and lt like below but I would like to override the min or max so that I'll be able to use something like max(a, b, c ,d). The class will have multiple property as well, but I think 2 for this example is sufficient.
class MyClass:
def __init__(self, item1, item2):
self.item1 = item1
self.item2 = item2
def __gt__(self, other):
if isinstance(other, MyClass):
if self.item1 > other.item1:
return True
elif self.item1 <= other.item1:
return False
elif self.item2 > other.item2:
return True
elif self.item2 <= other.item2:
return False
def __lt__(self, other):
if isinstance(other, MyClass):
if self.item1 < other.item1:
return True
elif self.item1 >= other.item1:
return False
elif self.item2 < other.item2:
return True
elif self.item2 >= other.item2:
return False
Ex:
a = MyClass(2,3)
b = MyClass(3,3)
print(a > b)
# False
I tried overriding __cmp__ but that doesnt seem to work.
Would like to be able to do max(a, b) and return b object
python max min
edited Nov 14 '18 at 3:29
Aqueous Carlos
301313
asked Nov 14 '18 at 3:24
user1179317user1179317
607818
You can already callmax(a, b, c, ...)with an arbitrary number of arguments, and it'll return whichever is largest, by comparing them to each other. It uses__gt__and__lt__to do this, to the best of my knowledge. You can't overridemax()itself, unfortunately, because it's a built-in method and isn't bound to a specific class (though you could easily write your own method to do the same thing if you wanted). Is there a specific thing you wantmax()to do here that it doesn't do already, and if so could you give a clearer example?
– Green Cloak Guy
Nov 14 '18 at 3:29
(1) You are already returningbviamax(a, b).max(a, b) is b
– Brad Solomon
Nov 14 '18 at 3:31
(2) Considerfunctools.total_ordering
– Brad Solomon
Nov 14 '18 at 3:31
(3)max(a, b, c ,d)is also already valid. What specifically is wrong with what you've written now?
– Brad Solomon
Nov 14 '18 at 3:32
1
Don't forget thereturn NotImplementedfor when the other object isn't an instance of the expected class.
– user2357112
Nov 14 '18 at 5:32
|
show 3 more comments
-1
-1
-1
Not sure the best way to title this question, but how can I override or perform min(a, b) or max(a, b) on objects of a class i made? I can override the gt and lt like below but I would like to override the min or max so that I'll be able to use something like max(a, b, c ,d). The class will have multiple property as well, but I think 2 for this example is sufficient.
class MyClass:
def __init__(self, item1, item2):
self.item1 = item1
self.item2 = item2
def __gt__(self, other):
if isinstance(other, MyClass):
if self.item1 > other.item1:
return True
elif self.item1 <= other.item1:
return False
elif self.item2 > other.item2:
return True
elif self.item2 <= other.item2:
return False
def __lt__(self, other):
if isinstance(other, MyClass):
if self.item1 < other.item1:
return True
elif self.item1 >= other.item1:
return False
elif self.item2 < other.item2:
return True
elif self.item2 >= other.item2:
return False
Ex:
a = MyClass(2,3)
b = MyClass(3,3)
print(a > b)
# False
I tried overriding __cmp__ but that doesnt seem to work.
Would like to be able to do max(a, b) and return b object
python max min
edited Nov 14 '18 at 3:29
Aqueous Carlos
301313
asked Nov 14 '18 at 3:24
user1179317user1179317
607818
Not sure the best way to title this question, but how can I override or perform min(a, b) or max(a, b) on objects of a class i made? I can override the gt and lt like below but I would like to override the min or max so that I'll be able to use something like max(a, b, c ,d). The class will have multiple property as well, but I think 2 for this example is sufficient.
class MyClass:
def __init__(self, item1, item2):
self.item1 = item1
self.item2 = item2
def __gt__(self, other):
if isinstance(other, MyClass):
if self.item1 > other.item1:
return True
elif self.item1 <= other.item1:
return False
elif self.item2 > other.item2:
return True
elif self.item2 <= other.item2:
return False
def __lt__(self, other):
if isinstance(other, MyClass):
if self.item1 < other.item1:
return True
elif self.item1 >= other.item1:
return False
elif self.item2 < other.item2:
return True
elif self.item2 >= other.item2:
return False
Ex:
a = MyClass(2,3)
b = MyClass(3,3)
print(a > b)
# False
I tried overriding __cmp__ but that doesnt seem to work.
Would like to be able to do max(a, b) and return b object
python max min
python max min
edited Nov 14 '18 at 3:29
Aqueous Carlos
301313
asked Nov 14 '18 at 3:24
user1179317user1179317
607818
edited Nov 14 '18 at 3:29
Aqueous Carlos
301313
asked Nov 14 '18 at 3:24
user1179317user1179317
607818
edited Nov 14 '18 at 3:29
Aqueous Carlos
301313
edited Nov 14 '18 at 3:29
Aqueous Carlos
301313
edited Nov 14 '18 at 3:29
Aqueous Carlos
301313
301313
asked Nov 14 '18 at 3:24
user1179317user1179317
607818
asked Nov 14 '18 at 3:24
user1179317user1179317
607818
asked Nov 14 '18 at 3:24
user1179317user1179317
607818
607818
You can already callmax(a, b, c, ...)with an arbitrary number of arguments, and it'll return whichever is largest, by comparing them to each other. It uses__gt__and__lt__to do this, to the best of my knowledge. You can't overridemax()itself, unfortunately, because it's a built-in method and isn't bound to a specific class (though you could easily write your own method to do the same thing if you wanted). Is there a specific thing you wantmax()to do here that it doesn't do already, and if so could you give a clearer example?
– Green Cloak Guy
Nov 14 '18 at 3:29
(1) You are already returningbviamax(a, b).max(a, b) is b
– Brad Solomon
Nov 14 '18 at 3:31
(2) Considerfunctools.total_ordering
– Brad Solomon
Nov 14 '18 at 3:31
(3)max(a, b, c ,d)is also already valid. What specifically is wrong with what you've written now?
– Brad Solomon
Nov 14 '18 at 3:32
1
Don't forget thereturn NotImplementedfor when the other object isn't an instance of the expected class.
– user2357112
Nov 14 '18 at 5:32
|
show 3 more comments
You can already callmax(a, b, c, ...)with an arbitrary number of arguments, and it'll return whichever is largest, by comparing them to each other. It uses__gt__and__lt__to do this, to the best of my knowledge. You can't overridemax()itself, unfortunately, because it's a built-in method and isn't bound to a specific class (though you could easily write your own method to do the same thing if you wanted). Is there a specific thing you wantmax()to do here that it doesn't do already, and if so could you give a clearer example?
– Green Cloak Guy
Nov 14 '18 at 3:29
(1) You are already returningbviamax(a, b).max(a, b) is b
– Brad Solomon
Nov 14 '18 at 3:31
(2) Considerfunctools.total_ordering
– Brad Solomon
Nov 14 '18 at 3:31
(3)max(a, b, c ,d)is also already valid. What specifically is wrong with what you've written now?
– Brad Solomon
Nov 14 '18 at 3:32
1
Don't forget thereturn NotImplementedfor when the other object isn't an instance of the expected class.
– user2357112
Nov 14 '18 at 5:32
You can already call
max(a, b, c, ...) with an arbitrary number of arguments, and it'll return whichever is largest, by comparing them to each other. It uses __gt__ and __lt__ to do this, to the best of my knowledge. You can't override max() itself, unfortunately, because it's a built-in method and isn't bound to a specific class (though you could easily write your own method to do the same thing if you wanted). Is there a specific thing you want max() to do here that it doesn't do already, and if so could you give a clearer example?– Green Cloak Guy
Nov 14 '18 at 3:29
You can already call
max(a, b, c, ...) with an arbitrary number of arguments, and it'll return whichever is largest, by comparing them to each other. It uses __gt__ and __lt__ to do this, to the best of my knowledge. You can't override max() itself, unfortunately, because it's a built-in method and isn't bound to a specific class (though you could easily write your own method to do the same thing if you wanted). Is there a specific thing you want max() to do here that it doesn't do already, and if so could you give a clearer example?– Green Cloak Guy
Nov 14 '18 at 3:29
(1) You are already returning
b via max(a, b). max(a, b) is b– Brad Solomon
Nov 14 '18 at 3:31
(1) You are already returning
b via max(a, b). max(a, b) is b– Brad Solomon
Nov 14 '18 at 3:31
(2) Consider
functools.total_ordering– Brad Solomon
Nov 14 '18 at 3:31
(2) Consider
functools.total_ordering– Brad Solomon
Nov 14 '18 at 3:31
(3)
max(a, b, c ,d) is also already valid. What specifically is wrong with what you've written now?– Brad Solomon
Nov 14 '18 at 3:32
(3)
max(a, b, c ,d) is also already valid. What specifically is wrong with what you've written now?– Brad Solomon
Nov 14 '18 at 3:32
1
1
Don't forget the
return NotImplemented for when the other object isn't an instance of the expected class.– user2357112
Nov 14 '18 at 5:32
Don't forget the
return NotImplemented for when the other object isn't an instance of the expected class.– user2357112
Nov 14 '18 at 5:32
|
show 3 more comments
1 Answer
1
active
oldest
votes
0
Just override the comparison magic methods
class A(object):
def __init__(self, value):
self.value = value
def __lt__(self, other):
return self.value < other.value
def __lt__(self, other):
return self.value <= other.value
def __eq__(self, other):
return self.value == other.value
def __ne__(self, other):
return self.value != other.value
def __gt__(self, other):
return self.value > other.value
def __ge__(self, other):
return self.value < other.value
def __str__(self):
return str(self.value)
a = A(10)
b = A(20)
min(a, b)
answered Nov 14 '18 at 5:25
Muruganandhan PeramagounderMuruganandhan Peramagounder
11
add a comment |
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1 Answer
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1 Answer
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oldest
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0
Just override the comparison magic methods
class A(object):
def __init__(self, value):
self.value = value
def __lt__(self, other):
return self.value < other.value
def __lt__(self, other):
return self.value <= other.value
def __eq__(self, other):
return self.value == other.value
def __ne__(self, other):
return self.value != other.value
def __gt__(self, other):
return self.value > other.value
def __ge__(self, other):
return self.value < other.value
def __str__(self):
return str(self.value)
a = A(10)
b = A(20)
min(a, b)
answered Nov 14 '18 at 5:25
Muruganandhan PeramagounderMuruganandhan Peramagounder
11
add a comment |
0
Just override the comparison magic methods
class A(object):
def __init__(self, value):
self.value = value
def __lt__(self, other):
return self.value < other.value
def __lt__(self, other):
return self.value <= other.value
def __eq__(self, other):
return self.value == other.value
def __ne__(self, other):
return self.value != other.value
def __gt__(self, other):
return self.value > other.value
def __ge__(self, other):
return self.value < other.value
def __str__(self):
return str(self.value)
a = A(10)
b = A(20)
min(a, b)
answered Nov 14 '18 at 5:25
Muruganandhan PeramagounderMuruganandhan Peramagounder
11
add a comment |
0
0
0
Just override the comparison magic methods
class A(object):
def __init__(self, value):
self.value = value
def __lt__(self, other):
return self.value < other.value
def __lt__(self, other):
return self.value <= other.value
def __eq__(self, other):
return self.value == other.value
def __ne__(self, other):
return self.value != other.value
def __gt__(self, other):
return self.value > other.value
def __ge__(self, other):
return self.value < other.value
def __str__(self):
return str(self.value)
a = A(10)
b = A(20)
min(a, b)
answered Nov 14 '18 at 5:25
Muruganandhan PeramagounderMuruganandhan Peramagounder
11
Just override the comparison magic methods
class A(object):
def __init__(self, value):
self.value = value
def __lt__(self, other):
return self.value < other.value
def __lt__(self, other):
return self.value <= other.value
def __eq__(self, other):
return self.value == other.value
def __ne__(self, other):
return self.value != other.value
def __gt__(self, other):
return self.value > other.value
def __ge__(self, other):
return self.value < other.value
def __str__(self):
return str(self.value)
a = A(10)
b = A(20)
min(a, b)
answered Nov 14 '18 at 5:25
Muruganandhan PeramagounderMuruganandhan Peramagounder
11
edited Nov 14 '18 at 5:31
answered Nov 14 '18 at 5:25
Muruganandhan PeramagounderMuruganandhan Peramagounder
11
answered Nov 14 '18 at 5:25
Muruganandhan PeramagounderMuruganandhan Peramagounder
11
answered Nov 14 '18 at 5:25
Muruganandhan PeramagounderMuruganandhan Peramagounder
11
11
add a comment |
add a comment |
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You can already call
max(a, b, c, ...)with an arbitrary number of arguments, and it'll return whichever is largest, by comparing them to each other. It uses__gt__and__lt__to do this, to the best of my knowledge. You can't overridemax()itself, unfortunately, because it's a built-in method and isn't bound to a specific class (though you could easily write your own method to do the same thing if you wanted). Is there a specific thing you wantmax()to do here that it doesn't do already, and if so could you give a clearer example?– Green Cloak Guy
Nov 14 '18 at 3:29
(1) You are already returning
bviamax(a, b).max(a, b) is b– Brad Solomon
Nov 14 '18 at 3:31
(2) Consider
functools.total_ordering– Brad Solomon
Nov 14 '18 at 3:31
(3)
max(a, b, c ,d)is also already valid. What specifically is wrong with what you've written now?– Brad Solomon
Nov 14 '18 at 3:32
1
Don't forget the
return NotImplementedfor when the other object isn't an instance of the expected class.– user2357112
Nov 14 '18 at 5:32