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Rank function in MySQL
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270
One option is to use a ranking variable, such as the following:
SELECT first_name,
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What is the easiest way to push an element to the beginning of the array?
...elf, moving other elements upwards.
And in use:
irb>> a = [ 0, 1, 2]
=> [0, 1, 2]
irb>> a.unshift('x')
=> ["x", 0, 1, 2]
irb>> a.inspect
=> "["x", 0, 1, 2]"
share
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im...
Converting a column within pandas dataframe from int to string
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142
In [16]: df = DataFrame(np.arange(10).reshape(5,2),columns=list('AB'))
In [17]: df
Out[17]:
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Export Postgresql table data using pgAdmin
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edited Nov 25 '16 at 15:06
Alfonso Tienda
2,72511 gold badge1313 silver badges2727 bronze badges
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Finding the index of elements based on a condition using python list comprehension
...t all, but just deal with the values—[value for value in a if value > 2]. Usually dealing with indexes means you're not doing something the best way.
If you do need an API similar to Matlab's, you would use numpy, a package for multidimensional arrays and numerical math in Python which is heavi...
Is there a way to pass optional parameters to a function?
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The Python 2 documentation, 7.6. Function definitions gives you a couple of ways to detect whether a caller supplied an optional parameter.
First, you can use special formal parameter syntax *. If the function definition has a formal p...
Accessing bash command line args $@ vs $*
...rs are quoted. Let me illustrate the differences:
$ set -- "arg 1" "arg 2" "arg 3"
$ for word in $*; do echo "$word"; done
arg
1
arg
2
arg
3
$ for word in $@; do echo "$word"; done
arg
1
arg
2
arg
3
$ for word in "$*"; do echo "$word"; done
arg 1 arg 2 arg 3
$ for word in "$@"; do echo "$...
Custom Python list sorting
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Charlie
6,5234545 silver badges5050 bronze badges
answered Aug 7 '12 at 16:44
miles82miles82
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How do I check the difference, in seconds, between two dates?
...ates, use total_seconds like this:
import datetime as dt
a = dt.datetime(2013,12,30,23,59,59)
b = dt.datetime(2013,12,31,23,59,59)
(b-a).total_seconds()
86400.0
#note that seconds doesn't give you what you want:
(b-a).seconds
0
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CPU Privilege Rings: Why rings 1 and 2 aren't used?
...of the modern protection model) only has a concept of privileged (ring 0,1,2) and unprivileged, the benefit to rings 1 and 2 were diminished greatly.
The intent by Intel in having rings 1 and 2 is for the OS to put device drivers at that level, so they are privileged, but somewhat separated from th...