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What does “hashable” mean in Python?

...if it has a hash value which never changes during its lifetime (it needs a __hash__() method), and can be compared to other objects (it needs an __eq__() or __cmp__() method). Hashable objects which compare equal must have the same hash value. Hashability makes an object usable as a dictionary ...
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How to import classes defined in __init__.py

... 'lib/'s parent directory must be in sys.path. Your 'lib/__init__.py' might look like this: from . import settings # or just 'import settings' on old Python versions class Helper(object): pass Then the following example should work: from lib.settings import Values from l...
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efficient circular buffer?

...1] #[10, 11, 3, 8] 3, 11 Class: class circularlist(object): def __init__(self, size, data = []): """Initialization""" self.index = 0 self.size = size self._data = list(data)[-size:] def append(self, value): """Append an element""" if le...
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Use of 'prototype' vs. 'this' in JavaScript?

...hich can be accessed with Object.getPrototypeOf(myObject) or with myObject.__proto__ in some browsers. The proto property indicates the object's parent in the prototype chain (or the object from which this object inherits). The prototype property (which is only on functions) indicated the object t...
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Split data frame string column into multiple columns

... Use stringr::str_split_fixed library(stringr) str_split_fixed(before$type, "_and_", 2) share | improve this answer | ...
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Import a file from a subdirectory?

....org/tutorial/modules.html In short, you need to put a blank file named __init__.py in the "lib" directory. share | improve this answer | follow | ...
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What is __declspec and when do I need to use it?

I have seen instances of __declspec in the code that I am reading. What is it? And when would I need to use this construct? ...
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relative path in require_once doesn't work

... Use __DIR__ to get the current path of the script and this should fix your problem. So: require_once(__DIR__.'/../class/user.php'); This will prevent cases where you can run a PHP script from a different folder and therefo...
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What is the difference between class and instance attributes?

...> a.foo.append(5) >>> b.foo [5] >>> class A: ... def __init__(self): self.foo = [] >>> a, b = A(), A() >>> a.foo.append(5) >>> b.foo [] share | ...
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What does functools.wraps do?

...r. In other words, if you have a decorator def logged(func): def with_logging(*args, **kwargs): print(func.__name__ + " was called") return func(*args, **kwargs) return with_logging then when you say @logged def f(x): """does some math""" return x + x * x it's ex...