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Python's equivalent of && (logical-and) in an if-statement
...actually
evaluated because of the print statements:
>>> def print_and_return(value):
... print(value)
... return value
>>> res = print_and_return(False) and print_and_return(True)
False
As you can see only one print statement is executed, so Python really didn't even lo...
Is gcc's __attribute__((packed)) / #pragma pack unsafe?
...
Yes, __attribute__((packed)) is potentially unsafe on some systems. The symptom probably won't show up on an x86, which just makes the problem more insidious; testing on x86 systems won't reveal the problem. (On the x86, misalig...
enum - getting value of enum on string conversion
...;>> member.name
'red'
>>> member.value
1
You could add a __str__ method to your enum, if all you wanted was to provide a custom string representation:
class D(Enum):
def __str__(self):
return str(self.value)
x = 1
y = 2
Demo:
>>> from enum import E...
How to remove an element from a list by index
...ook at svn.python.org/projects/python/trunk/Objects/listobject.c how PyList_GetItem() essentially returns ((PyListObject *)op) -> ob_item[i]; - the ith element of an array.
– glglgl
Sep 9 '13 at 7:53
...
Standard alternative to GCC's ##__VA_ARGS__ trick?
...
It is possible to avoid the use of GCC's ,##__VA_ARGS__ extension if you are willing to accept some hardcoded upper limit on the number of arguments you can pass to your variadic macro, as described in Richard Hansen's answer to this question. If you do not want to hav...
Convert nested Python dict to object?
...']
The alternative (original answer contents) is:
class Struct:
def __init__(self, **entries):
self.__dict__.update(entries)
Then, you can use:
>>> args = {'a': 1, 'b': 2}
>>> s = Struct(**args)
>>> s
<__main__.Struct instance at 0x01D6A738>
>>...
What do I use for a max-heap implementation in Python?
...y heapq, and that there is no good alternative.
– ire_and_curses
Jun 10 '10 at 17:46
24
@gatoatig...
How to avoid having class data shared among instances?
...
You want this:
class a:
def __init__(self):
self.list = []
Declaring the variables inside the class declaration makes them "class" members and not instance members. Declaring them inside the __init__ method makes sure that a new instance of th...
How do I check for C++11 support?
...
There is a constant named __cplusplus that C++ compilers should set to the version of the C++ standard supported see this
#if __cplusplus <= 199711L
#error This library needs at least a C++11 compliant compiler
#endif
It is set to 199711L in V...
How to implement an ordered, default dict? [duplicate]
...eredDict):
# Source: http://stackoverflow.com/a/6190500/562769
def __init__(self, default_factory=None, *a, **kw):
if (default_factory is not None and
not isinstance(default_factory, Callable)):
raise TypeError('first argument must be callable')
Ordered...