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Elegant way to invert a map in Scala
...
Assuming values are unique, this works:
(Map() ++ origMap.map(_.swap))
On Scala 2.8, however, it's easier:
origMap.map(_.swap)
Being able to do that is part of the reason why Scala 2.8 has a new collection library.
...
Why can't I use a list as a dict key in python?
...le, it'll work correctly with classes that have a custom comparison method __eq__. But if you convert them to strings, everything is compared by its string representation.
– Aran-Fey
May 20 '18 at 12:50
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Aren't Python strings immutable? Then why does a + “ ” + b work?
...
Consider:
>>> a='asdf'
>>> a.__repr__
<method-wrapper '__repr__' of str object at 0x1091aab90>
>>> a='asdf'
>>> a.__repr__
<method-wrapper '__repr__' of str object at 0x1091aab90>
>>> a='qwer'
>>> a.__repr_...
GET URL parameter in PHP
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$_GET is not a function or language construct—it's just a variable (an array). Try:
<?php
echo $_GET['link'];
In particular, it's a superglobal: a built-in variable that's populated by PHP and is available in all scope...
What to put in a python module docstring? [closed]
...
NAME
x - This module does blah blah.
FILE
/tmp/x.py
CLASSES
__builtin__.object
Blah
class Blah(__builtin__.object)
| This class does blah blah.
|
| Data and other attributes defined here:
|
| __dict__ = <dictproxy object>
| ...
Real world example about how to use property feature in python?
...changing terms.
Complex calculation hidden behind an attribute:
class PDB_Calculator(object):
...
@property
def protein_folding_angle(self):
# number crunching, remote server calls, etc
# all results in an angle set in 'some_angle'
# It could also reference a ca...
Named routes _path vs _url
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_path helpers provide a site-root-relative path. You should probably use this most of the time.
_url helpers provide an absolute path, including protocol and server name. I've found that I mainly use these in emails when cre...
Removing duplicate objects with Underscore for Javascript
...t = [{a:1,b:5},{a:1,c:5},{a:2},{a:3},{a:4},{a:3},{a:2}];
var uniqueList = _.uniq(list, function(item, key, a) {
return item.a;
});
// uniqueList = [Object {a=1, b=5}, Object {a=2}, Object {a=3}, Object {a=4}]
Notes:
Callback return value used for comparison
First comparison object with un...
Can we define implicit conversions of enums in c#?
...rmined from reflection
/// </summary>
private string _name;
/// <summary>
/// The DescriptionAttribute, if any, linked to the declaring field
/// </summary>
private DescriptionAttribute _descriptionAttribute;
/// <summary...
What is getattr() exactly and how do I use it?
...answered Apr 10 '19 at 9:42
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