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Is it possible to make abstract classes in Python?
...nitions of those methods:
>>> Abstract()
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
TypeError: Can't instantiate abstract class Abstract with abstract methods foo
>>> class StillAbstract(Abstract):
... pass
...
>>> StillAbstr...
List comprehension rebinds names even after scope of comprehension. Is this right?
...list
comprehensions blindingly fast, and
while it was not a common pitfall for
beginners, it definitely stung people
occasionally. For generator
expressions we could not do this.
Generator expressions are implemented
using generators, whose execution
requires a separate execution fra...
When to favor ng-if vs. ng-show/ng-hide?
...ise the difference:
ng-if will remove elements from DOM. This means that all your handlers or anything else attached to those elements will be lost. For example, if you bound a click handler to one of child elements, when ng-if evaluates to false, that element will be removed from DOM and your cli...
Verify a certificate chain using openssl verify
...ing the first part of the post Greg references (the second part is specifically about pyOpenSSL and not relevant to this question).
In case the post goes away I'll quote the important paragraphs:
Unfortunately, an "intermediate" cert that is actually a root / self-signed
will be treated as a ...
Inline SVG in CSS
...possible. I just went to the standard specification and stated it was virtually impossible, which turned out to be a mistake (sort of)
– toniedzwiedz
May 26 '12 at 19:05
18
...
Creating a singleton in Python
...mple implementation:
class Singleton(type):
_instances = {}
def __call__(cls, *args, **kwargs):
if cls not in cls._instances:
cls._instances[cls] = super(Singleton, cls).__call__(*args, **kwargs)
return cls._instances[cls]
class Logger(object):
__meta...
How to “perfectly” override a dict?
...or other builtins) directly. It often makes no sense, because what you actually want to do is implement the interface of a dict. And that is exactly what ABCs are for.
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...
Is the creation of Java class files deterministic?
...nces? Is a difference only possibly in theory or does Oracle's javac actually produce different class files for the same input and compiler options?
...
Get exception description and stack trace which caused an exception, all as a string
...
See the traceback module, specifically the format_exc() function. Here.
import traceback
try:
raise ValueError
except ValueError:
tb = traceback.format_exc()
else:
tb = "No error"
finally:
print tb
...
Bidirectional 1 to 1 Dictionary in C#
...turn firstToSecond.Count; }
}
/// <summary>
/// Removes all items from the dictionary.
/// </summary>
public void Clear()
{
firstToSecond.Clear();
secondToFirst.Clear();
}
}
...