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Positive Number to Negative Number in JavaScript?
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13 Answers
13
Active
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Converting a Pandas GroupBy output from Series to DataFrame
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g1 here is a DataFrame. It has a hierarchical index, though:
In [19]: type(g1)
Out[19]: pandas.core.frame.DataFrame
In [20]: g1.index
Out[20]:
MultiIndex([('Alice', 'Seattle'), ('Bob', 'Seattle'), ('Mallory', 'Portland'),
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Function for Factorial in Python
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192
Easiest way is to use math.factorial (available in Python 2.6 and above):
import math
math.fa...
How to remove the first and the last character of a string
...o
var yourString = "/installers/";
var result = yourString.substring(1, yourString.length-1);
console.log(result);
Or you can use .slice as suggested by Ankit Gupta
var yourString = "/installers/services/";
var result = yourString.slice(1,-1);
console.log(result);
D...
What does the “map” method do in Ruby?
...e from the block (the original object is unchanged unless you use map!):
[1, 2, 3].map { |n| n * n } #=> [1, 4, 9]
Array and Range are enumerable types. map with a block returns an Array. map! mutates the original array.
Where is this helpful, and what is the difference between map! and each...
How to add leading zeros?
...of digits to begin with, so let's try a harder example of making powers of 10 width 8 too.
anim <- 25499:25504
x <- 10 ^ (0:5)
paste (and it's variant paste0) are often the first string manipulation functions that you come across. They aren't really designed for manipulating numbers, but...
Standard deviation of a list
I want to find mean and standard deviation of 1st, 2nd,... digits of several (Z) lists. For example, I have
8 Answers
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How do I profile memory usage in Python?
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123
This one has been answered already here: Python memory profiler
Basically you do something li...
Jasmine.js comparing arrays
...n() {
it('passes if arrays are equal', function() {
var arr = [1, 2, 3];
expect(arr).toEqual([1, 2, 3]);
});
});
Just for information:
toBe() versus toEqual(): toEqual() checks equivalence. toBe(), on the
other hand, makes sure that they're the exact same object.
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Strange, unexpected behavior (disappearing/changing values) when using Hash default value, e.g. Hash
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166
First, note that this behavior applies to any default value that is subsequently mutated (e.g....