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ValueError: The truth value of an array with more than one element is ambiguous. Use a.any() or a.al
...wo arrays to be evaluated in boolean context (by
calling __bool__ in Python3 or __nonzero__ in Python2).
Your original code
mask = ((r["dt"] >= startdate) & (r["dt"] <= enddate))
selected = r[mask]
looks correct. However, if you do want and, then instead of a and b use (a-b).any() or ...
ImportError in importing from sklearn: cannot import name check_build
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13 Answers
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How do API Keys and Secret Keys work? Would it be secure if I have to pass my API and secret keys to
...ow api keys and secret keys work. Just 2 days ago I signed up for Amazon S3 and installed the S3Fox Plugin . They asked me for both my Access Key and Secret Access Key, both of which require me to login to access.
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Random string generation with upper case letters and digits
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31 Answers
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What does ~~ (“double tilde”) do in Javascript?
... because the bitwise operators implicitly convert their operands to signed 32-bit integers. This works whether the operands are (floating-point) numbers or strings, and the result is a number.
In other words, it yields:
function(x) {
if(x < 0) return Math.ceil(x);
else return Math.floor(x);...
PostgreSQL error 'Could not connect to server: No such file or directory'
...grate in my project or even try most database tasks for my Ruby on Rails 3.2 applications.
22 Answers
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How do I disable orientation change on Android?
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Update April 2013: Don't do this. It wasn't a good idea in 2009 when I first answered the ques...
Finding three elements in an array whose sum is closest to a given number
...P: Given an array A of n integers and a target value S, does there exist a 3-tuple from A that sums to S?
modified problem P': Given an array A of n integers, does there exist a 3-tuple from A that sums to zero?
Notice that you can go from this version of the problem P' from P by subtracting ...