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What is “entropy and information gain”?
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1051
I assume entropy was mentioned in the context of building decision trees.
To illustrate, ima...
LAST_INSERT_ID() MySQL
... think must be quite easy. I need to return the LAST INSERTED ID from table1 when I run the following MySql query:
11 Answe...
How to retrieve GET parameters from javascript? [duplicate]
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17 Answers
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How to generate random number with the specific length in python
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189
To get a random 3-digit number:
from random import randint
randint(100, 999) # randint is in...
Logic to test that 3 of 4 are True
....7/4) indicates that converting bool to int gives the expected values 0 or 1.
In Java and C#, you can use the following construct:
if ((a?1:0) + (b?1:0) + (c?1:0) + (d?1:0) == 3)
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How to get subarray from array?
I have var ar = [1, 2, 3, 4, 5] and want some function getSubarray(array, fromIndex, toIndex) , that result of call getSubarray(ar, 1, 3) is new array [2, 3, 4] .
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Convert absolute path into relative path given a current directory using Bash
...U coreutils 8.23 is the simplest, I think:
$ realpath --relative-to="$file1" "$file2"
For example:
$ realpath --relative-to=/usr/bin/nmap /tmp/testing
../../../tmp/testing
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Items in JSON object are out of order using “json.dumps”?
... to sort the keys:
>>> import json
>>> json.dumps({'a': 1, 'b': 2})
'{"b": 2, "a": 1}'
>>> json.dumps({'a': 1, 'b': 2}, sort_keys=True)
'{"a": 1, "b": 2}'
If you need a particular order; you could use collections.OrderedDict:
>>> from collections import Ordere...
What's the difference between a proc and a lambda in Ruby?
...e:
p = Proc.new {|a, b| puts a**2+b**2 } # => #<Proc:0x3c7d28@(irb):1>
p.call 1, 2 # => 5
p.call 1 # => NoMethodError: undefined method `**' for nil:NilClass
p.call 1, 2, 3 # => 5
l = lambda {|a, b| puts a**2+b**2 } # => #<Proc:0x15016c@(irb):5 (lambda)>
l.call 1, 2 # =&g...