为什么 Python 3.7 数据类不支持 < > <= 和 >=，或者它们支持吗？
Why don't Python 3.7 dataclasses support < > <= and >=, or do they?
对于Transcrypt Python to JavaScript compiler I am currently using the new @dataclass decorator. I had expected that ==, !=, <, >, >=, <= would be supported, as per the PEP's abstract的3.7.1版本，但好像不是这样的：
from dataclasses import dataclass
@dataclass
class C:
x: int = 10
有些比较无效：
>>> c1 = C(1)
>>> c2 = C(2)
>>> c1 == c2 # ok
False
>>> c1 < c2 # crash
TypeError: '<' not supported between instances of 'C' and 'C'
除了 == 和 != 之外，为什么不支持比较运算符？还是我忽略了什么？
他们有，只是不是默认的。每 PEP-557:
The parameters to dataclass are:
...
order: If true (the default is False), __lt__, __le__, __gt__, and __ge__ methods will be generated. These compare the
class as if it were a tuple of its fields, in order. Both instances in
the comparison must be of the identical type. If order is true and
eq is false, a ValueError is raised.
所以你想要@dataclass(order=True).
对于Transcrypt Python to JavaScript compiler I am currently using the new @dataclass decorator. I had expected that ==, !=, <, >, >=, <= would be supported, as per the PEP's abstract的3.7.1版本，但好像不是这样的：
from dataclasses import dataclass
@dataclass
class C:
x: int = 10
有些比较无效：
>>> c1 = C(1)
>>> c2 = C(2)
>>> c1 == c2 # ok
False
>>> c1 < c2 # crash
TypeError: '<' not supported between instances of 'C' and 'C'
除了 == 和 != 之外，为什么不支持比较运算符？还是我忽略了什么？
他们有，只是不是默认的。每 PEP-557:
The parameters to
dataclassare:...
order: If true (the default is False),__lt__,__le__,__gt__, and__ge__methods will be generated. These compare the class as if it were a tuple of its fields, in order. Both instances in the comparison must be of the identical type. Iforderis true andeqis false, aValueErroris raised.
所以你想要@dataclass(order=True).