Describing Callables
- Generally, a callable is something that can be called
- The method name
__call__()is called when the instance is called as a function - The following class uses the special method:
>>> class Foo:
... def __call__(self):
... print('Called')
>>> f = Foo()
>>> print(f)
<__main__.Foo at 0x1062bab00>
>>> f()
'Called'Practical Example of Function Emulation
>>> class DistanceFrom(object):
... def __init__(self,origin):
... self.origin = origin
... def __call__(self, x):
... return abs(x - self.origin)
>>> nums = [1, 37, 42, 101, 13, 9, -20]
>>> nums.sort(key=DistanceFrom(10))
>>> print(nums)
[9, 13, 1, 37, -20, 42, 101]Summarizing Special Methods
| Method | Description |
|---|---|
__call__ |
Emulates a function |
References
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