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What does “hashable” mean in Python?
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From the Python glossary:
An object is hashable 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 s...
Is it possible to implement a Python for range loop without an iterator variable?
Is it possible to do following without the i ?
14 Answers
14
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std::function and std::bind: what are they, and when should they be used?
I know what functors are and when to use them with std algorithms, but I haven't understood what Stroustrup says about them in the C++11 FAQ .
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What is a Python equivalent of PHP's var_dump()? [duplicate]
When debugging in PHP, I frequently find it useful to simply stick a var_dump() in my code to show me what a variable is, what its value is, and the same for anything that it contains.
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ValidateAntiForgeryToken purpose, explanation and example
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MVC's anti-forgery support writes a unique value to an HTTP-only cookie and then the same value is written to the form. When the page is submitted, an error is raised if the cookie value doesn't match the form value.
It's important to note that the feat...
How to disable GCC warnings for a few lines of code
In Visual C++, it's possible to use #pragma warning (disable: ...) . Also I found that in GCC you can override per file compiler flags . How can I do this for "next line", or with push/pop semantics around areas of code using GCC?
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Lazy Method for Reading Big File in Python?
I have a very big file 4GB and when I try to read it my computer hangs.
So I want to read it piece by piece and after processing each piece store the processed piece into another file and read next piece.
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Is the list of Python reserved words and builtins available in a library?
...', 'nonlocal', 'not', 'or', 'pass', 'raise', 'return', 'try',
'while', 'with', 'yield']
If you want to include built-in names as well (Python 3), then check the builtins module:
>>> import builtins
>>> dir(builtins)
['ArithmeticError', 'AssertionError', 'AttributeError',
'Bas...
How to run code when a class is subclassed? [duplicate]
...t is to define a subclass of type -- i.e. a metaclass.
A metaclass is to its class as a class is to its instance.
In Python2 you would define the metaclass of a class with
class SuperClass:
__metaclass__ = Watcher
where Watcher is a subclass of type.
In Python3 the syntax has been chang...
GCC dump preprocessor defines
Is there a way for gcc/g++ to dump its preprocessor defines from the command line?
I mean things like __GNUC__ , __STDC__ , and so on.
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