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Python list subtraction operation
...t to use the - infix syntax, you can just do:
class MyList(list):
def __init__(self, *args):
super(MyList, self).__init__(args)
def __sub__(self, other):
return self.__class__(*[item for item in self if item not in other])
you can then use it like:
x = MyList(1, 2, 3, 4...
How to access the ith column of a NumPy multidimensional array?
...0,2]] = something would modify test, and not create another array. But copy_test = test[:, [0,2]] does in fact create a copy as you say.
– Akavall
Apr 11 '14 at 16:19
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Does Python have “private” variables in classes?
... want to emulate private variables for some reason, you can always use the __ prefix from PEP 8. Python mangles the names of variables like __foo so that they're not easily visible to code outside the class that contains them (although you can get around it if you're determined enough, just like you...
python: how to identify if a variable is an array or a scalar
...o uses numpy often, I'd recommend a very pythonic test of:
if hasattr(N, "__len__")
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How to find memory leak in a C++ code/project?
.... The most common and most easy way to detect is, define a macro say, DEBUG_NEW and use it, along with predefined macros like __FILE__ and __LINE__ to locate the memory leak in your code. These predefined macros tell you the file and line number of memory leaks.
DEBUG_NEW is just a MACRO which is u...
Why aren't superclass __init__ methods automatically invoked?
Why did the Python designers decide that subclasses' __init__() methods don't automatically call the __init__() methods of their superclasses, as in some other languages? Is the Pythonic and recommended idiom really like the following?
...
Multiple columns index when using the declarative ORM extension of sqlalchemy
...e just Column objects, index=True flag works normally:
class A(Base):
__tablename__ = 'table_A'
id = Column(Integer, primary_key=True)
a = Column(String(32), index=True)
b = Column(String(32), index=True)
if you'd like a composite index, again Table is present here as usual you ju...
Python: access class property from string [duplicate]
...k just perfectly if source names ANY attribute of self, including the other_data in your example.
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putting current class as return type annotation [duplicate]
...he annotations at function definition time. Instead, they are preserved in __annotations__ in string form. This is called Postponed Evaluation of Annotations, introduced in PEP 563.
Also note:
Deprecation policy
Starting with Python 3.7, a __future__ import is required to use the
descri...
Combining C++ and C - how does #ifdef __cplusplus work?
...tive.
Now, specifically regarding your numbered questions:
Regarding #1: __cplusplus will stay defined inside of extern "C" blocks. This doesn't matter, though, since the blocks should nest neatly.
Regarding #2: __cplusplus will be defined for any compilation unit that is being run through the C...