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What is the purpose of the single underscore “_” variable in Python?
What is the meaning of _ after for in this code?
5 Answers
5
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Accessing class variables from a list comprehension in the class definition
...(1)]
... return Foo
...
>>> dis.dis(foo)
2 0 LOAD_BUILD_CLASS
1 LOAD_CONST 1 (<code object Foo at 0x10a436030, file "<stdin>", line 2>)
4 LOAD_CONST 2 ('Foo')
7 MAKE_FUNCTION ...
Should I use a class or dictionary?
...vantage? What happens if you later want to add some code? Where would your __init__ code go?
Classes are for bundling related data (and usually code).
Dictionaries are for storing key-value relationships, where usually the keys are all of the same type, and all the values are also of one type. Occ...
Split data frame string column into multiple columns
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Use stringr::str_split_fixed
library(stringr)
str_split_fixed(before$type, "_and_", 2)
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Dynamic instantiation from string name of a class in dynamically imported module?
...
You can use getattr
getattr(module, class_name)
to access the class. More complete code:
module = __import__(module_name)
class_ = getattr(module, class_name)
instance = class_()
As mentioned below, we may use importlib
import importlib
module = importlib.imp...
TypeError: module.__init__() takes at most 2 arguments (3 given)
...ample.responses import Response
class GeoJsonResponse(Response):
def __init__(self, geo_json_data):
Looks fine. No problems until you try to debug the thing, which is when you get a bunch of seemingly vague error messages like this:
from pyexample.responses import GeoJsonResponse
..\py...
How to get a reference to current module's attributes in Python
...he way I typically see this done is like this:
import sys
dir(sys.modules[__name__])
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Why does the expression 0 < 0 == 0 return False in Python?
...bool(0) or bool(1) before this thought experiment
– j_syk
May 20 '11 at 15:45
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Is there a better way to express nested namespaces in C++ within the header
...ry rare cases in C++ where I actually like the use of #defines.
#define MY_COMPANY_BEGIN namespace MyCompany { // begin of the MyCompany namespace
#define MY_COMPANY_END } // end of the MyCompany namespace
#define MY_LIBRARY_BEGIN namespace MyLibrary { // begin of the MyLib...
Django filter queryset __in for *every* item in list
...oManyField('Tag')
class Tag(models.Model):
name = models.CharField(max_length=50)
def __unicode__(self):
return self.name
In [2]: t1 = Tag.objects.create(name='holiday')
In [3]: t2 = Tag.objects.create(name='summer')
In [4]: p = Photo.objects.create()
In [5]: p.tags.add(t1)
In [6]...