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How do I retrieve the number of columns in a Pandas data frame?
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312
Like so:
import pandas as pd
df = pd.DataFrame({"pear": [1,2,3], "apple": [2,3,4], "orange": [...
John Carmack's Unusual Fast Inverse Square Root (Quake III)
...ulates the inverse square root of a float, 4x faster than regular (float)(1.0/sqrt(x)) , including a strange 0x5f3759df constant. See the code below. Can someone explain line by line what exactly is going on here and why this works so much faster than the regular implementation?
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How to get a variable name as a string in PHP?
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edited Nov 1 '08 at 1:11
answered Nov 1 '08 at 0:42
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How to right align widget in horizontal linear layout Android?
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18 Answers
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For i = 0, why is (i += i++) equal to 0?
...; // i=0 because the ++ is a postfix operator and hasn't been executed
i + 1; // Note that you are discarding the calculation result
What actually happens is more involved than that - take a look at MSDN, 7.5.9 Postfix increment and decrement operators:
The run-time processing of a postfix inc...
how do i remove a comma off the end of a string?
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Best way to represent a fraction in Java?
...arable<BigFraction>
{
private static final long serialVersionUID = 1L; //because Number is Serializable
private final BigInteger numerator;
private final BigInteger denominator;
public final static BigFraction ZERO = new BigFraction(BigInteger.ZERO, BigInteger.ONE, true);
public fin...
How do Google+ +1 widgets break out of their iframe?
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181
The Google +1 widget is JavaScript that runs on your website that is building an iframe. Thi...
How to create a temporary directory?
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answered Jan 8 '11 at 2:30
moinudinmoinudin
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