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Is it possible to have multiple statements in a python lambda expression?
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17 Answers
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What is the difference between bottom-up and top-down?
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251
rev4: A very eloquent comment by user Sammaron has noted that, perhaps, this answer previousl...
Need a simple explanation of the inject method
I'm looking at this code but my brain is not registering how the number 10 can become the result. Would someone mind explaining what's happening here?
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Patterns for handling batch operations in REST web services?
...xample, to delete several messages at once.
DELETE /mail?&id=0&id=1&id=2
It's a little more complicated to batch update partial resources, or resource attributes. That is, update each markedAsRead attribute. Basically, instead of treating the attribute as part of each resource, you tr...
Is there an R function for finding the index of an element in a vector?
... that is equal to x . I know that one way to do this is: which(x == v)[[1]] , but that seems excessively inefficient. Is there a more direct way to do it?
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Unique (non-repeating) random numbers in O(1)?
I'd like to generate unique random numbers between 0 and 1000 that never repeat (i.e. 6 doesn't show up twice), but that doesn't resort to something like an O(N) search of previous values to do it. Is this possible?
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Disable migrations when running unit tests in Django 1.7
Django 1.7 introduced database migrations .
7 Answers
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Get index of array element faster than O(n)
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Convert the array into a hash. Then look for the key.
array = ['a', 'b', 'c']
hash = Hash[arr...
Boolean operators && and ||
...an return a vector, like this:
((-2:2) >= 0) & ((-2:2) <= 0)
# [1] FALSE FALSE TRUE FALSE FALSE
The longer form evaluates left to right examining only the first element of each vector, so the above gives
((-2:2) >= 0) && ((-2:2) <= 0)
# [1] FALSE
As the help page says...