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Why is “if not someobj:” better than “if someobj == None:” in Python?
...r not ? This is done using the following algorithm :
If the object has a __nonzero__ special method (as do numeric built-ins, int and float), it calls this method. It must either return a bool value which is then directly used, or an int value that is considered False if equal to zero.
Otherwise, ...
Boost Statechart vs. Meta State Machine
...se who argued for exit separation from destructors in statechart (argument based on a real use case, about interaction with the real world i.e. I/O) way back when it was submitted to Boost I agree there can be issues in putting exit logic in destructors. David Abrahams unsurprisingly made persuasive...
Microsoft CDN for jQuery or Google CDN? [closed]
...
Update based on comments:
Short version: It doesn't matter much, but it may depend on what they host. They all host different things: Google doesn't host jQuery.Validate, Microsoft did not host jQuery-UI, since 2016 they do!!, ...
How to add “active” class to Html.ActionLink in ASP.NET MVC
...tp://getbootstrap.com/components/#navbar
The way you handle your UI style based on what is active or not has nothing to do with ASP.NET MVC's ActionLink helper. This is the proper solution to follow how the Bootstrap framework was built.
<ul class="nav navbar-nav">
<li class="active"&...
Underscore vs Double underscore with variables and methods [duplicate]
Somebody was nice enough to explain to me that __method() mangles but instead of bothering him further since there are a lot of other people who need help I was wondering if somebody could elaborate the differences further.
...
What does the “at” (@) symbol do in Python?
...
Example
class Pizza(object):
def __init__(self):
self.toppings = []
def __call__(self, topping):
# When using '@instance_of_pizza' before a function definition
# the function gets passed onto 'topping'.
self.toppings.appe...
Skip rows during csv import pandas
...me of the data that you have obtained from this U.S. Geological Survey database
may not have received Director's approval. ... agency_cd site_no datetime tz_cd 139719_00065 139719_00065_cd
5s 15s 20d 6s 14n 10s USGS 08041780 2018-05-06 00:00 CDT 1.98 A
It would...
correct way to define class variables in Python [duplicate]
...hey are just two different kinds of class elements:
Elements outside the __init__ method are static elements; they belong to the class.
Elements inside the __init__ method are elements of the object (self); they don't belong to the class.
You'll see it more clearly with some code:
class MyClass...
Remove all special characters from a string in R?
...e, you want the str_replace_all from the stringr package, though gsub from base R works just as well.
The exact regular expression depends upon what you are trying to do. You could just remove those specific characters that you gave in the question, but it's much easier to remove all punctuation c...
Finding the source code for built-in Python functions?
... particular module or function is implemented in you can usually print the __file__ attribute. Alternatively, you may use the inspect module, see the section Retrieving Source Code in the documentation of inspect.
For built-in classes and methods this is not so straightforward since inspect.getfile...