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Get the index of the nth occurrence of a string?
...if you think about it. (IndexOf will return as soon as it finds the match, and you'll keep going from where it left off.)
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Factors in R: more than an annoyance?
... data types in R is factors. In my experience factors are basically a pain and I never use them. I always convert to characters. I feel oddly like I'm missing something.
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Which equals operator (== vs ===) should be used in JavaScript comparisons?
I'm using JSLint to go through JavaScript, and it's returning many suggestions to replace == (two equals signs) with === (three equals signs) when doing things like comparing idSele_UNVEHtype.value.length == 0 inside of an if statement.
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Accessing class variables from a list comprehension in the class definition
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Class scope and list, set or dictionary comprehensions, as well as generator expressions do not mix.
The why; or, the official word on this
In Python 3, list comprehensions were given a proper scope (local namespace) of their own, to p...
Seedable JavaScript random number generator
The JavaScript Math.random() function returns a random value between 0 and 1, automatically seeded based on the current time (similar to Java I believe). However, I don't think there's any way to set you own seed for it.
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What does -1 mean in numpy reshape?
... (-1,3) but not (-1, -1)). It simply means that it is an unknown dimension and we want numpy to figure it out. And numpy will figure this by looking at the 'length of the array and remaining dimensions' and making sure it satisfies the above mentioned criteria
Now see the example.
z = np.array([[...
Cartesian product of multiple arrays in JavaScript
...the newly added flatMap.
Special thanks to ECMAScript 2019 for adding flat and flatMap to the language!
Example
This is the exact example from your question:
let output = cartesian([1,2],[10,20],[100,200,300]);
Output
This is the output of that command:
[ [ 1, 10, 100 ],
[ 1, 10, 200 ],
[ 1, 10...
Why use the params keyword?
...ly doing to make the best choice.
– Allen Clark Copeland Jr
Nov 28 '15 at 22:15
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Python progression path - From apprentice to guru
I've been learning, working, and playing with Python for a year and a half now. As a biologist slowly making the turn to bio-informatics, this language has been at the very core of all the major contributions I have made in the lab. I more or less fell in love with the way Python permits me to expre...
MySQL ON vs USING?
In a MySQL JOIN , what is the difference between ON and USING() ? As far as I can tell, USING() is just more convenient syntax, whereas ON allows a little more flexibility when the column names are not identical. However, that difference is so minor, you'd think they'd just do away with USI...