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How can I convert this foreach code to Parallel.ForEach?
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edited Jul 26 '13 at 9:06
Contango
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answ...
Pandas get topmost n records within each group
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>>> df.groupby('id').head(2)
id value
id
1 0 1 1
1 1 2
2 3 2 1
4 2 2
3 7 3 1
4 8 4 1
(Keep in mind that you might need to order/sort before, depending on your data)
EDIT: As mentioned by the questioner, use df.gro...
How do you create nested dict in Python?
...ers
f.next()
# get first colum as keys
keys = (line.split(',')[0] for line in f)
# create empty dictionary:
d = {}
# read from file b.csv
with open(b_file) as f:
# gather headers except first key header
headers = f.next().split(',')[1:]
# iterate lines
for line in f:
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Rails mapping array of hashes onto single hash
...g a method call between each element of it.
For example [1, 2, 3].reduce(0, :+) is like saying 0 + 1 + 2 + 3 and gives 6.
In our case we do something similar, but with the merge function, which merges two hashes.
[{:a => 1}, {:b => 2}, {:c => 3}].reduce({}, :merge)
is {}.merge({:a =&g...
How to drop into REPL (Read, Eval, Print, Loop) from Python code
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105
You could try using the interactive option for python:
python -i program.py
This will execut...
Easiest way to copy a single file from host to Vagrant guest?
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108
Instead of using a shell provisioner to copy the file, you can also use a Vagrant file provisio...
Selecting multiple columns in a pandas dataframe
...s of the first two columns) then you can do this instead:
df1 = df.iloc[:, 0:2] # Remember that Python does not slice inclusive of the ending index.
Additionally, you should familiarize yourself with the idea of a view into a Pandas object vs. a copy of that object. The first of the above methods w...
How do I merge a git tag onto a branch
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edited Jun 11 '13 at 20:08
answered Jun 11 '13 at 19:44
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How to add new item to hash
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307
Create the hash:
hash = {:item1 => 1}
Add a new item to it:
hash[:item2] = 2
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What does this gdb output mean?
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203
That is a confirmed bug of the iOS SDK 5 / Simulator - happens as soon as the simulator tries t...