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Reverse / invert a dictionary mapping
...g aspect of this new implementation is considered an implementation detail and should not be relied upon. There is no guarantee it will stay that way so don't write code relying on Dict having the same behavior as OrderedDict.
– Mattias
Aug 26 '18 at 17:44
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Filter dict to contain only certain keys?
...nary comprehension.
If you use a version which lacks them (ie Python 2.6 and earlier), make it dict((your_key, old_dict[your_key]) for ...). It's the same, though uglier.
Note that this, unlike jnnnnn's version, has stable performance (depends only on number of your_keys) for old_dicts of any siz...
Any way to properly pretty-print ordered dictionaries?
I like the pprint module in Python. I use it a lot for testing and debugging. I frequently use the width option to make sure the output fits nicely within my terminal window.
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Using CSS for a fade-in effect on page load
... text-align: center;
-webkit-animation: fadein 2s; /* Safari, Chrome and Opera > 12.1 */
-moz-animation: fadein 2s; /* Firefox < 16 */
-ms-animation: fadein 2s; /* Internet Explorer */
-o-animation: fadein 2s; /* Opera < 12.1 */
animation: fadein 2s...
Simultaneously merge multiple data.frames in a list
... issue here is that each data.frame differs in terms of the number of rows and columns, but they all share the key variables (which I've called "var1" and "var2" in the code below). If the data.frames were identical in terms of columns, I could merely rbind , for which plyr's rbind.fill would...
Iterating over dictionaries using 'for' loops
...:
will simply loop over the keys in the dictionary, rather than the keys and values. To loop over both key and value you can use the following:
For Python 3.x:
for key, value in d.items():
For Python 2.x:
for key, value in d.iteritems():
To test for yourself, change the word key to poop.
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How do I obtain the frequencies of each value in an FFT?
... an FFT result. These are stored in two double arrays: a real part array and an imaginary part array. How do I determine the frequencies that correspond to each element in these arrays?
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Get querystring from URL using jQuery [duplicate]
... Object containing the URL parameters:
// Read a page's GET URL variables and return them as an associative array.
function getUrlVars()
{
var vars = [], hash;
var hashes = window.location.href.slice(window.location.href.indexOf('?') + 1).split('&');
for(var i = 0; i < hashes.len...
Simple (non-secure) hash function for JavaScript? [duplicate]
... can simply call .hashCode() on any string, e.g. "some string".hashCode(), and receive a numerical hash code (more specifically, a Java equivalent) such as 1395333309.
String.prototype.hashCode = function() {
var hash = 0;
if (this.length == 0) {
return hash;
}
for (var i =...
How can I write text on a HTML5 canvas element?
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Is there any way to get the font width and size so we can center it? (Dynamic content)
– Oliver Dixon
Dec 30 '14 at 2:20
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