enum
ast
nomail at com.invalid
Tue Oct 31 06:48:26 EDT 2017
Hi
Below an example of enum which defines an __init__
method.
https://docs.python.org/3.5/library/enum.html#planet
Documentation says that the value of the enum
members will be passed to this method.
But in that case __init__ waits for two arguments, mass
and radius, while enum member's value is a tuple.
It seems that there is a tuple unpacking, but it is
not documented, that's not clear
class Planet(Enum):
... MERCURY = (3.303e+23, 2.4397e6)
... VENUS = (4.869e+24, 6.0518e6)
... EARTH = (5.976e+24, 6.37814e6)
... MARS = (6.421e+23, 3.3972e6)
... JUPITER = (1.9e+27, 7.1492e7)
... SATURN = (5.688e+26, 6.0268e7)
... URANUS = (8.686e+25, 2.5559e7)
... NEPTUNE = (1.024e+26, 2.4746e7)
...
... def __init__(self, mass, radius):
... self.mass = mass # in kilograms
... self.radius = radius # in meters
...
... @property
... def surface_gravity(self):
... # universal gravitational constant (m3 kg-1 s-2)
... G = 6.67300E-11
... return G * self.mass / (self.radius * self.radius)
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