subclass

For numpy.ndarray subclass, ufunc outputs have the same type. This is good in general but I would like for ufunc with scalar output to return scalar type (such as numpy.float64 ). Example: import numpy as np class MyArray(np.ndarray): def __new__(cls, array): obj = np.asarray(array).view(cls) return obj a = MyArray(np.arange(5)) a*2 # MyArray([0, 2, 4, 6, 8]) => same class as original (i.e. MyArray), ok a.sum() # MyArray(10) => same as original, but here I'd expect np.int64 type(2*a) is type(a.sum()) # True b = a.view(np.ndarray) type(2*b) is type(b.sum()) # False For standard numpy array,

I am ignoring the warnings and trying to subclass a pandas DataFrame. My reasons for doing so are as follows: I want to retain all the existing methods of DataFrame . I want to set a few additional attributes at class instantiation, which will later be used to define additional methods that I can call on the subclass. Here's a snippet: class SubFrame(pd.DataFrame): def __init__(self, *args, **kwargs): freq = kwargs.pop('freq', None) ddof = kwargs.pop('ddof', None) super(SubFrame, self).__init__(*args, **kwargs) self.freq = freq self.ddof = ddof self.index.freq = pd.tseries.frequencies.to

This question is in relation to posts at What does 'super' do in Python? , How do I initialize the base (super) class? , and Python: How do I make a subclass from a superclass? which describes two ways to initialize a SuperClass from within a SubClass as class SuperClass: def __init__(self): return def superMethod(self): return ## One version of Initiation class SubClass(SuperClass): def __init__(self): SuperClass.__init__(self) def subMethod(self): return or class SuperClass: def __init__(self): return def superMethod(self): return ## Another version of Initiation class SubClass(SuperClass):

I have a project with a Tab Bar, and a custom Navigation bar for each of the tabs. Each of the Navigation bar UIViews have a height constraint constant set in the storyboard. I would like to subclass this NSLayoutConstraint (for the Nav height), so that it changes the height for iPhone X. The Navigation bar needs to be much taller on an iPhone X, and since I'm not using "out of the box" objects, my constraints need to be manually set. Essentially, I want to do something like the following in the subclass, so I don't have to repeat a bunch of code and make unnecessary outlets: override func