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How to express infinity in Ruby?
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If you use ruby 1.9.2, you can use:
>> Float::INFINITY #=> Infinity
>> 3 < Float::INFINITY #=> true
Or you can create your own constant using the following*:
I've checked that in Ruby 1.8.6, 1.8.7, and 1.9.2 you have Floa...
How to copy directories in OS X 10.7.3?
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2 Answers
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leading zeros in rails
...ed with padstr; otherwise, returns str.
some_int = 5
some_int.to_s.rjust(2, '0') # => '05'
some_int.to_s.rjust(5, '0') # => '00005'
another_int = 150
another_int.to_s.rjust(2, '0') # => '150'
another_int.to_s.rjust(3, '0') # => '150'
another_int.to_s.rjust(5, '0') # => '00150'
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Convert numpy array to tuple
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>>> arr = numpy.array(((2,2),(2,-2)))
>>> tuple(map(tuple, arr))
((2, 2), (2, -2))
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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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How to write multiple line string using Bash with variables?
...the command used (echo) is wrong.
Correct would be:
#!/bin/bash
kernel="2.6.39"
distro="xyz"
cat >/etc/myconfig.conf <<EOL
line 1, ${kernel}
line 2,
line 3, ${distro}
line 4 line
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EOL
cat /etc/myconfig.conf
This construction is referred to as a Here Document and can be found in t...
How to run cron job every 2 hours
...n I write a Crontab that will run my /home/username/test.sh script every 2 hours?
5 Answers
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Python Dictionary to URL Parameters
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256
Use urllib.urlencode(). It takes a dictionary of key-value pairs, and converts it into a form ...
Boolean operators && and ||
...rter ones are vectorized, meaning they can return a vector, like this:
((-2:2) >= 0) & ((-2:2) <= 0)
# [1] FALSE FALSE TRUE FALSE FALSE
The longer form evaluates left to right examining only the first element of each vector, so the above gives
((-2:2) >= 0) && ((-2:2) <...
Asterisk in function call
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182
* is the "splat" operator: It takes a list as input, and expands it into actual positional argum...