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Can a decorator of an instance method access the class?
...decorator, perhaps something like this (warning: untested code).
def class_decorator(cls):
for name, method in cls.__dict__.iteritems():
if hasattr(method, "use_class"):
# do something with the method and class
print name, cls
return cls
def method_decorator(v...
difference between variables inside and outside of __init__()
...
Variable set outside __init__ belong to the class. They're shared by all instances.
Variables created inside __init__ (and all other method functions) and prefaced with self. belong to the object instance.
...
What does “mro()” do?
...
Follow along...:
>>> class A(object): pass
...
>>> A.__mro__
(<class '__main__.A'>, <type 'object'>)
>>> class B(A): pass
...
>>> B.__mro__
(<class '__main__.B'>, <class '__main__.A'>, <type 'object'>)
>>> class C(A): pa...
How to print to console in pytest?
...as printed to standard out in that particular test.
For example,
def test_good():
for i in range(1000):
print(i)
def test_bad():
print('this should fail!')
assert False
Results in the following output:
>>> py.test tmp.py
============================= test session s...
What is __init__.py for?
What is __init__.py for in a Python source directory?
12 Answers
12
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How to import classes defined in __init__.py
...
'lib/'s parent directory must be in sys.path.
Your 'lib/__init__.py' might look like this:
from . import settings # or just 'import settings' on old Python versions
class Helper(object):
pass
Then the following example should work:
from lib.settings import Values
from l...
Why does Python use 'magic methods'?
...s', e.g. to make its length available, an object implements a method, def __len__(self) , and then it is called when you write len(obj) .
...
NSLog the method name with Objective-C in iPhone
...
print(__FUNCTION__) // Swift
NSLog(@"%@", NSStringFromSelector(_cmd)); // Objective-C
Swift 3 and above
print(#function)
share
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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...
Ruby send vs __send__
I understand the concept of some_instance.send but I'm trying to figure out why you can call this both ways. The Ruby Koans imply that there is some reason beyond providing lots of different ways to do the same thing. Here are the two examples of usage:
...