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What are paramorphisms?
...foldr c n xs)
para c n [] = n
foldr c n [] = n
Some people call paramorphisms "primitive recursion" by contrast with catamorphisms (foldr) being "iteration".
Where foldr's two parameters are given a recursively computed value for each recursive subobject of the input data (here, that...
How to unset a JavaScript variable?
I have a global variable in JavaScript (actually a window property, but I don't think it matters) which was already populated by a previous script but I don't want another script that will run later to see its value or that it was even defined.
...
How to get one value at a time from a generator function in Python?
...
In Python <= 2.5, use gen.next(). This will work for all Python 2.x versions, but not Python 3.x
In Python >= 2.6, use next(gen). This is a built in function, and is clearer. It will also work in Python 3.
Both of these end up calling a specially named function, next(), wh...
How to clear the interpreter console?
Like most Python developers, I typically keep a console window open with the Python interpreter running to test commands, dir() stuff, help() stuff , etc.
...
Preferred method to store PHP arrays (json_encode vs serialize)
...ciative array of data in a flat file for caching purposes. I might occasionally come across the need to convert it to JSON for use in my web app but the vast majority of the time I will be using the array directly in PHP.
...
window.close and self.close do not close the window in Chrome
...ec for window.close():
The close() method on Window objects should, if all the following conditions are met, close the browsing context A:
The corresponding browsing context A is script-closable.
The browsing context of the incumbent script is familiar with the browsing context A.
Th...
How do I keep Python print from adding newlines or spaces? [duplicate]
...ys.stdout.flush()
sys.stdout.write('m')
sys.stdout.flush()
You need to call sys.stdout.flush() because otherwise it will hold the text in a buffer and you won't see it.
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lodash multi-column sortBy descending
...dash.com/docs#orderBy) in Lodash as of 4.3.0. The normal sort function is called _.sortBy(lodash.com/docs#sortBy)
– Nidhin David
Feb 12 '16 at 11:19
2
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append multiple values for one key in a dictionary [duplicate]
...st of values associated with that year, right? Here's how I'd do it:
years_dict = dict()
for line in list:
if line[0] in years_dict:
# append the new number to the existing array at this slot
years_dict[line[0]].append(line[1])
else:
# create a new array in this slo...
What is __init__.py for?
...kages as they existed in Python 3.2 and earlier. A regular package is typically implemented as a directory containing an __init__.py file. When a regular package is imported, this __init__.py file is implicitly executed, and the objects it defines are bound to names in the package’s namespace. The...