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Calling parent class __init__ with multiple inheritance, what's the right way?
...s to greater flexibility for subclasses.
In the direct call approach, C.__init__ can call both A.__init__ and B.__init__.
When using super(), the classes need to be designed for cooperative multiple inheritance where C calls super, which invokes A's code which will also call super which invokes ...
Understanding __get__ and __set__ and Python descriptors
... how Python's property type is implemented. A descriptor simply implements __get__, __set__, etc. and is then added to another class in its definition (as you did above with the Temperature class). For example:
temp=Temperature()
temp.celsius #calls celsius.__get__
Accessing the property you assi...
What are metaclasses in Python?
... the 'class' statement) by calling the metaclass. Combined with the normal __init__ and __new__ methods, metaclasses therefore allow you to do 'extra things' when creating a class, like registering the new class with some registry or replace the class with something else entirely.
When the class st...
How do I get the full path of the current file's directory?
...3
For the directory of the script being run:
import pathlib
pathlib.Path(__file__).parent.absolute()
For the current working directory:
import pathlib
pathlib.Path().absolute()
Python 2 and 3
For the directory of the script being run:
import os
os.path.dirname(os.path.abspath(__file__))
I...
correct way to use super (argument passing)
...ich unlike object, absorbs/ignores arguments:
class Base(object):
def __init__(self, *args, **kwargs): pass
class A(Base):
def __init__(self, *args, **kwargs):
print "A"
super(A, self).__init__(*args, **kwargs)
class B(Base):
def __init__(self, *args, **kwargs):
...
Why does this loop produce “warning: iteration 3u invokes undefined behavior” and output more than 4
...e is the full assembly listing:
.file "a.cpp"
.section .text$_ZNKSt5ctypeIcE8do_widenEc,"x"
.linkonce discard
.align 2
LCOLDB0:
LHOTB0:
.align 2
.p2align 4,,15
.globl __ZNKSt5ctypeIcE8do_widenEc
.def __ZNKSt5ctypeIcE8do_widenEc; .scl 2; .type 32; .e...
How to fix “Attempted relative import in non-package” even with __init__.py
...
Yes. You're not using it as a package.
python -m pkg.tests.core_test
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What does functools.wraps do?
...r. In other words, if you have a decorator
def logged(func):
def with_logging(*args, **kwargs):
print(func.__name__ + " was called")
return func(*args, **kwargs)
return with_logging
then when you say
@logged
def f(x):
"""does some math"""
return x + x * x
it's ex...
UML class diagram enum
...
They are simply showed like this:
_______________________
| <<enumeration>> |
| DaysOfTheWeek |
|_____________________|
| Sunday |
| Monday |
| Tuesday |
| ... |
|____________________...
Why does += behave unexpectedly on lists?
...
The general answer is that += tries to call the __iadd__ special method, and if that isn't available it tries to use __add__ instead. So the issue is with the difference between these special methods.
The __iadd__ special method is for an in-place addition, that is it mut...