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What are free monads?
...r monad, and the second one gives you a way to "get out" of it.
More generally, if X is a Y with some extra stuff P, then a "free X" is a a way of getting from a Y to an X without gaining anything extra.
Examples: a monoid (X) is a set (Y) with extra structure (P) that basically says it has an ope...
Python assigning multiple variables to same value? list behavior
...the same identical value. Variables have types, identities, addresses, and all kinds of stuff like that.
Names don't have any of that. Values do, of course, and you can have lots of names for the same value.
If you give Notorious B.I.G. a hot dog,* Biggie Smalls and Chris Wallace have a hot dog. ...
What's the best way to iterate over two or more containers simultaneously
...wrote this wrapper around boost range: a function with one line of code is all I need. However, I would be interested if the performance of boost ranges is optimal as well.
– SebastianK
Nov 6 '14 at 15:45
...
How do I implement interfaces in python?
...interface, a module that is a part of the Zope Component Architecture, a really awesomely cool component framework. Here you don't subclass from the interfaces, but instead mark classes (or even instances) as implementing an interface. This can also be used to look up components from a component reg...
How do you use the ellipsis slicing syntax in Python?
... item):
... if item is Ellipsis:
... return "Returning all items"
... else:
... return "return %r items" % item
...
>>> x = TestEllipsis()
>>> print x[2]
return 2 items
>>> print x[...]
Returning all items
Of course, there is the ...
Check if a file exists with wildcard in shell script [duplicate]
...p;& echo "files do exist" || echo "files do not exist"
## This is all we needed to know, so we can break after the first iteration
break
done
This is very similar to @grok12's answer, but it avoids the unnecessary iteration through the whole list.
...
Text Progress Bar in the Console [closed]
...any of the answers below that I use regularly (no imports required).
Note: All code in this answer was created for Python 3; see end of answer to use this code with Python 2.
# Print iterations progress
def printProgressBar (iteration, total, prefix = '', suffix = '', decimals = 1, length = 100, fil...
Recursive search and replace in text files on Mac and Linux
...the linux shell, the following command will recursively search and replace all instances of 'this' with 'that' (I don't have a Linux shell in front of me, but it should do).
...
Why can't Python parse this JSON data?
... You have [] when you should have {}:
[] are for JSON arrays, which are called list in Python
{} are for JSON objects, which are called dict in Python
Here's how your JSON file should look:
{
"maps": [
{
"id": "blabla",
"iscategorical": "0"
},
...
Test for non-zero length string in Bash: [ -n “$var” ] or [ “$var” ]
...t, I'll use [ ! "$var" ] instead of [ -z "$var" ].
– AllenHalsey
Oct 6 '10 at 20:32
2
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