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Using property() on classmethods
... (using the classmethod() function) for getting and setting what is essentially a static variable. I tried to use the property() function with these, but it results in an error. I was able to reproduce the error with the following in the interpreter:
...
Migrating from JSF 1.2 to JSF 2.0
... JSP 2.x
If you're using JSP 2.x and want to keep using it, then you basically don't need to change anything else.
Gradually upgrading
If you're already using a suffix url-pattern for the FacesServlet, like *.jsf, then it's good to know that the FacesServlet will first scan for *.xhtml file and ...
Best practice for Python assert
...
To be able to automatically throw an error when x become less than zero throughout the function. You can use class descriptors. Here is an example:
class LessThanZeroException(Exception):
pass
class variable(object):
def __init__(self, va...
Getting SyntaxError for print with keyword argument end=' '
...print ("foo" % bar, end=" ")
or
print "foo" % bar, end=" "
i.e. as a call to print with a tuple as argument.
That's obviously bad syntax (literals don't take keyword arguments). In Python 3.x print is an actual function, so it takes keyword arguments, too.
The correct idiom in Python 2.x for ...
How to implement a queue with three stacks?
...r Sedgewick have confirmed they are not aware of a 3-stack solution within all the constraints of the original question
DETAILS
There are two implementations behind this link: http://www.eecs.usma.edu/webs/people/okasaki/jfp95/index.html
One of them is O(1) with three stacks BUT it uses lazy exe...
Elegant ways to support equivalence (“equality”) in Python classes
When writing custom classes it is often important to allow equivalence by means of the == and != operators. In Python, this is made possible by implementing the __eq__ and __ne__ special methods, respectively. The easiest way I've found to do this is the following method:
...
How to identify numpy types in python?
...o test for that. And so on. The point is, you have to know what you're actually asking for when you want to do something as unusual as loose manual type switching, but once you know, it's easy to implement.
– abarnert
Mar 11 '16 at 20:41
...
How do I execute a string containing Python code in Python?
...;>> x
4
However, the first step should be to ask yourself if you really need to. Executing code should generally be the position of last resort: It's slow, ugly and dangerous if it can contain user-entered code. You should always look at alternatives first, such as higher order functions, ...
What are good uses for Python3's “Function Annotations”
...
I think this is actually great.
Coming from an academic background, I can tell you that annotations have proved themselves invaluable for enabling smart static analyzers for languages like Java. For instance, you could define semantics like sta...
How is a CRC32 checksum calculated?
... 1 0000 0100 1100 0001 0001 1101 1011 0111
The highest term (x32) is usually not explicitly written, so it can instead be represented in hex just as
0x 04 C1 1D B7
Feel free to count the 1s and 0s, but you'll find they match up with the polynomial, where 1 is bit 0 (or the first bit) and x ...