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How can I get list of values from dict?
...ker?
[*L] vs. [].extend(L) vs. list(L)
small_ds = {x: str(x+42) for x in range(10)}
small_df = {x: float(x+42) for x in range(10)}
print('Small Dict(str)')
%timeit [*small_ds.values()]
%timeit [].extend(small_ds.values())
%timeit list(small_ds.values())
print('Small Dict(float)')
%timeit [*small...
How does grep run so fast?
...actually looks at (and it skips many
bytes entirely).
GNU grep uses raw Unix input system calls and avoids copying data
after reading it. Moreover, GNU grep AVOIDS BREAKING THE INPUT INTO
LINES. Looking for newlines would slow grep down by a factor of
several times, because to find th...
Finding differences between elements of a list
...lution:
>>> t = [1, 3, 6]
>>> v = [t[i+1]-t[i] for i in range(len(t)-1)]
>>> v
[2, 3]
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Access multiple elements of list knowing their index
...hList, ind: [searchList[i] for i in ind]
using the following input:
a = range(0, 10000000)
b = range(500, 500000)
simple python loop was the quickest with lambda operation a close second, mapIndexValues and getIndexValues were consistently pretty similar with numpy method significantly slower a...
How to get a DOM Element from a JQuery Selector
...
You can access the raw DOM element with:
$("table").get(0);
or more simply:
$("table")[0];
There isn't actually a lot you need this for however (in my experience). Take your checkbox example:
$(":checkbox").click(function() {
if ($(thi...
How to make good reproducible pandas examples
... this is similar to r's expand.grid(), see note 2 below
'd':np.repeat( range(3), 2 ),
'e':np.tile( range(2), 3 ),
# a date range and set of random dates
'f':pd.date_range('1/1/2011', periods=6, freq='D'),
'g':np.random.choice( pd.date_range('1/1/2011', periods=365,
...
What is the advantage to using bloom filters?
...is that you can have only one filter (you check whether the combination of user_id + article_id is there)
bitcoin uses bloom filter for wallet synchronization
Akamai's web servers use Bloom filters to prevent "one-hit-wonders" from being stored in its disk caches. One-hit-wonders are web objects req...
Convert a list to a dictionary in Python
...mprehension, but ironically I think the simplest way to do it will be with range() and len(), which would normally be a code smell.
b = {a[i]: a[i+1] for i in range(0, len(a), 2)}
So the iter()/izip() method is still probably the most Pythonic in Python 3, although as EOL notes in a comment, zip(...
How Do I Convert an Integer to a String in Excel VBA?
...e compounding with another String variable or constant. Like this:
Sheet1.Range("A1").Value = "My favorite number is " & 7
"My favorite number is 7"
So, really, the only rare case is when you really want to store an integer value, into a variant or Cell value, when not also compounding w...
Encode html entities in javascript
...
You can use regex to replace any character in a given unicode range with its html entity equivalent. The code would look something like this:
var encodedStr = rawStr.replace(/[\u00A0-\u9999<>\&]/gim, function(i) {
return '&#'+i.charCodeAt(0)+';';
});
This code will r...