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Why is “if not someobj:” better than “if someobj == None:” in Python?
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In the first test, Python try to convert the object to a bool value if it is not already one. Roughly, we are asking the object : are you meaningful or not ? This is done using the following algorithm :
If the object has a __nonzero__ special method (as do numeric built-ins, int and float),...
Confused about __str__ on list in Python [duplicate]
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Python has two different ways to convert an object to a string: str() and repr(). Printing an object uses str(); printing a list containing an object uses str() for the list itself, but the implementation of list.__str__() calls repr() for ...
How do I allow HTTPS for Apache on localhost?
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(Screenshots courtesy of Neil Obremski and his helpful article - although now quite out-of-date.)
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What's the advantage of a Java enum versus a class with public static final fields?
...");. I change the signature of Foo::bar to public void bar(String foobar). Now the person who called someFoo will need to modify their code if they still want it to work.
– Jeffrey
Jul 15 '15 at 16:09
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How can you set class attributes from variable arguments (kwargs) in python
...s = {'a', 'b', 'c'}
self.__dict__.update((k, v) for k, v in kwargs.items() if k in allowed_keys)
you could filter the keys beforehand (use iteritems instead of items if you’re still using Python 2.x).
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PostgreSQL Crosstab Query
Does any one know how to create crosstab queries in PostgreSQL?
For example I have the following table:
6 Answers
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How can I get the version defined in setup.py (setuptools) in my package?
...ire("MyProject")[0].version
Store version string for use during install
If you want to go the other way 'round (which appears to be what other answer authors here appear to have thought you were asking), put the version string in a separate file and read that file's contents in setup.py.
You cou...
Can't install Ruby under Lion with RVM – GCC issues
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This answer was edited multiple times and now contains several alternative solutions. Try the simple “Edit 3” solution first.
Ruby 1.9.3-p125 and later have official support for clang, so if you are installing such a version you should not need GCC. If you’re...
How to view the Folder and Files in GAC?
I want to view the folders and sub folders in GAC . Also want to know about adding and removing from GAC .
5 Answers
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How to make a class JSON serializable
... "/foo/bar"}'
In that case you can merely call json.dumps(f.__dict__).
If you want more customized output then you will have to subclass JSONEncoder and implement your own custom serialization.
For a trivial example, see below.
>>> from json import JSONEncoder
>>> class MyEn...