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Python __call__ special method practical example
I know that __call__ method in a class is triggered when the instance of a class is called. However, I have no idea when I can use this special method, because one can simply create a new method and perform the same operation done in __call__ method and instead of calling the instance, you can c...
Django. Override save for model
...self._image_changed = True
# Or put whole logic in here
small = rescale_image(self.image,width=100,height=100)
self.image_small=SimpleUploadedFile(name,small_pic)
def get_image(self):
return self._image
image = property(get_image, set_image)
# this is ...
Refresh a page using PHP
How can I refresh a page using PHP periodically? If I can not do it by PHP, what is the best recommended scenario?
13 Answe...
How do I get the row count of a pandas DataFrame?
...[0].count()", "len(data.index)"],
xlabel="data rows"
)
EDIT: As @Dan Allen noted in the comments len(df.index) and df[0].count() are not interchangeable as count excludes NaNs,
share
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improve...
How do I initialize the base (super) class?
... and invoke their base class through super(), e.g.
class X(object):
def __init__(self, x):
pass
def doit(self, bar):
pass
class Y(X):
def __init__(self):
super(Y, self).__init__(123)
def doit(self, foo):
return super(Y, self).doit(foo)
Because python knows about old- an...
How to manually expand a special variable (ex: ~ tilde) in bash
...
Using eval is a horrible suggestion, it's really bad that it gets so many upvotes. You will run into all sorts of problems when the variable's value contains shell meta characters.
– user2719058
Aug 31 '14 at 19:47
...
How to use if statements in underscore.js templates?
...ue proposed in this answer is that you're stuck doing string interpolation all over again, which templates are supposed to solve for you. As of right now, _.template inserts a ; at the start of each compiled code tag. Thus, it can handle tags breaking between statements, but not inside of expression...
STL中map容器使用自定义key类型报错详解 - C/C++ - 清泛网 - 专注C/C++及内核技术
...定义一个结构体来试试：[cpp]view plaincopystructa{char*pName;intm_a;} 引言
STL的map容器中，key的类型是不是随意的呢？
实践
编写测试代码
定义一个结构体来试试：
struct a
{
char* pName;
int m_a;
};
...
map<a, int> mp;
a ...
Checking if an instance's class implements an interface?
...
As therefromhere points out, you can use class_implements(). Just as with Reflection, this allows you to specify the class name as a string and doesn't require an instance of the class:
interface IInterface
{
}
class TheClass implements IInterface
{
}
$interfaces = cl...
How to suppress scientific notation when printing float values?
...cify how many digit after the . you wish to display, this depends on how small is the floating number). See this example:
>>> a = -7.1855143557448603e-17
>>> '{:f}'.format(a)
'-0.000000'
as shown above, default is 6 digits! This is not helpful for our case example, so instead we...