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Prepend a level to a pandas MultiIndex
...to the columns by adding axis=1, since the df.columns doesn't have the "set_index" method like the index, which always bugs me.
– Rutger Kassies
Feb 10 '17 at 12:32
2
...
What does .SD stand for in data.table in R
... may help you see what .SD is:
DT[ , .SD[ , paste(x, v, sep="", collapse="_")], by=y]
# y V1
# 1: 1 a1_b3_c5
# 2: 3 a2_b4_c6
Basically, the by=y statement breaks the original data.table into these two sub-data.tables
DT[ , print(.SD), by=y]
# <1st sub-data.table, called '.SD' while i...
Linking static libraries to other static libraries
I have a small piece of code that depends on many static libraries (a_1-a_n). I'd like to package up that code in a static library and make it available to other people.
...
How to listen for changes to a MongoDB collection?
...ata. Replicas Sets function by listening to changes on this oplog and then applying the changes locally.
Does this sound familiar?
I cannot detail the whole process here, it is several pages of documentation, but the tools you need are available.
First some write-ups on the oplog
- Brief descri...
Bootstrap 3 offset on right not left
...shan's answer
Add this in the end of the calc-grid-column mixin in mixins/_grid-framework.scss, right below the $type == offset if condition.
@if ($type == offset-right) {
.col-#{$class}-offset-right-#{$index} {
margin-right: percentage(($index / $grid-columns));
}
}
Modi...
Parsing XML with namespace in Python via 'ElementTree'
...
@Jon: register_namespace only influences serialisation, not search.
– Martijn Pieters♦
Aug 20 '14 at 7:10
5
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How to determine if a list of polygon points are in clockwise order?
...formula above? It ends with "xn*y1 - x1*yn"; when I believe it should be "x_n y_{n+1} - y_n x_{n-1}" (in LaTeX, at least). On the other hand, it's been ten years since I took any linear algebra classes.
– Michael Eric Oberlin
May 25 '15 at 20:25
...
What are the obj and bin folders (created by Visual Studio) used for?
...n folder holds binary files, which are the actual executable code for your application or library.
Each of these folders are further subdivided into Debug and Release folders, which simply correspond to the project's build configurations. The two types of files discussed above are placed into the a...
detect key press in python?
...for pause and s for stop), and I would not like it to be something like raw_input that waits for the user's input before continuing execution. Anyone know how to do this in a while loop?
...
How to find and return a duplicate value in array
...rocess huge data set.
Looking for faster solution? Here you go!
def find_one_using_hash_map(array)
map = {}
dup = nil
array.each do |v|
map[v] = (map[v] || 0 ) + 1
if map[v] > 1
dup = v
break
end
end
return dup
end
It's linear, O(n), but now needs to manag...