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Test if lists share any items in python
... generally the fastest.
There are four common ways to test if two lists a and b share any items. The first option is to convert both to sets and check their intersection, as such:
bool(set(a) & set(b))
Because sets are stored using a hash table in Python, searching them is O(1) (see here for...
In Python, what is the difference between “.append()” and “+= []”?
...d will add one item to the list, while += will copy all elements of right-hand-side list into the left-hand-side list.
Update: perf analysis
Comparing bytecodes we can assume that append version wastes cycles in LOAD_ATTR + CALL_FUNCTION, and += version -- in BUILD_LIST. Apparently BUILD_LIST outw...
initialize a numpy array
Is there way to initialize a numpy array of a shape and add to it? I will explain what I need with a list example. If I want to create a list of objects generated in a loop, I can do:
...
What does $.when.apply($, someArray) do?
I'm reading about Deferreds and Promises and keep coming across $.when.apply($, someArray) . I'm a little unclear on what this does exactly, looking for an explanation that one line works exactly (not the entire code snippet). Here's some context:
...
What is a monad?
...t necessarily “good”. They are a pattern which is sometimes beneficial and sometimes not.
Do note that the monadic patten can be combined in a different way:
[1,2,3].flatMap(a => [a + 1].flatMap(b => b != 3 ? [b] : []))
Here the binding is nested rater than chained, but the result is the ...
Scala 2.8 breakOut
...at]) : That
Note that it has two parameters. The first is your function and the second is an implicit. If you do not provide that implicit, Scala will choose the most specific one available.
About breakOut
So, what's the purpose of breakOut? Consider the example given for the question, You tak...
pandas GroupBy columns with NaN (missing) values
...the same placeholder hack).
However, as described in another answer, from pandas 1.1 you have better control over this behavior, NA values are now allowed in the grouper using dropna=False
share
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What is the difference between dict.items() and dict.iteritems() in Python2?
Are there any applicable differences between dict.items() and dict.iteritems() ?
10 Answers
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Why do we use arrays instead of other data structures?
...gured the added "features" in programming languages had improved upon this and by that replaced them. I see now that they aren't replaced but rather given new life, so to speak.
...
Custom bullet symbol for elements in that is a regular character, and not an image
...ides a straightforward solution. Simply add list-style: none; to your rule and force the LIs to display with hanging indents. The rule will look something like this:
ul {
list-style: none;
margin-left: 0;
padding-left: 1em;
text-indent: -1em;
}
Either the padding or the margin needs to ...