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Append column to pandas dataframe
...ust looking for a join:
> dat1 = pd.DataFrame({'dat1': [9,5]})
> dat2 = pd.DataFrame({'dat2': [7,6]})
> dat1.join(dat2)
dat1 dat2
0 9 7
1 5 6
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How to convert a boolean array to an int array
...t;>> x
array([ True, False, True], dtype=bool)
>>> x + [1, 2, 3]
array([2, 2, 4])
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Convert a row of a data frame to vector
...
answered Jan 23 '13 at 16:42
Ben BolkerBen Bolker
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How to remove specific elements in a numpy array
...index)
For your specific question:
import numpy as np
a = np.array([1, 2, 3, 4, 5, 6, 7, 8, 9])
index = [2, 3, 6]
new_a = np.delete(a, index)
print(new_a) #Prints `[1, 2, 5, 6, 8, 9]`
Note that numpy.delete() returns a new array since array scalars are immutable, similar to strings in Python...
How do write IF ELSE statement in a MySQL query
...ably want to use a CASE expression.
They look like this:
SELECT col1, col2, (case when (action = 2 and state = 0)
THEN
1
ELSE
0
END)
as state from tbl1;
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What's the difference between “mod” and “remainder”?
...
There is a difference between modulus and remainder. For example:
-21 mod 4 is 3 because -21 + 4 x 6 is 3.
But -21 divided by 4 gives -5 with a remainder of -1.
For positive values, there is no difference.
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Why does Math.round(0.49999999999999994) return 1?
....1 This is a specification bug, for precisely this one pathological case.2 Java 7 no longer mandates this broken implementation.3
The problem
0.5+0.49999999999999994 is exactly 1 in double precision:
static void print(double d) {
System.out.printf("%016x\n", Double.doubleToLongBits(d));
}
...
No provider for “framework:jasmine”! (Resolving: framework:jasmine)
....0",
"grunt-contrib-jshint": "~0.7.1",
"grunt-contrib-uglify": "~0.2.0",
"grunt-contrib-watch": "~0.5.2",
"grunt-google-cdn": "~0.2.0",
"grunt-newer": "~0.5.4",
"grunt-ngmin": "~0.0.2",
"grunt-rev": "~0.1.0",
"grunt-svgmin": "~0.2.0",
"grunt-usemin": "~2.0.0",
...
Pandas dataframe get first row of each group
...
248
>>> df.groupby('id').first()
value
id
1 first
2 first
3 first
4...
Java SE 6 vs. JRE 1.6 vs. JDK 1.6 - What do these mean?
...uild 1.6.0_07-b06"), and the HotSpot version (on mine, that's "build 10.0-b23, mixed mode"). I suspect the "11.0" you are seeing is the HotSpot version.
Update: HotSpot is (or used to be, now they seem to use it to mean the whole VM) the just-in-time compiler that is built in to the Java Virtual M...