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Meaning of acronym SSO in the context of std::string
...tions of std::string create a small automatic array, something like char [20]. If you have a string that is 20 characters or smaller (given this example, the actual size varies), it stores it directly in that array. This avoids the need to call new at all, which speeds things up a bit.
EDIT:
I was...
new DateTime() vs default(DateTime)
...
206
No, they are identical.
default(), for any value type (DateTime is a value type) will always c...
How can I reset a react component including all transitively reachable state?
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206
To ensure that the implicit browser state you mention and state of children is reset, you can a...
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:
...
CentOS 64 bit bad ELF interpreter
...OURAPPNAME)
The output will look like this:
linux-gate.so.1 => (0xf7760000)
libpthread.so.0 => /lib/libpthread.so.0 (0xf773e000)
libSM.so.6 => not found
Check for missing libraries (e.g. libSM.so.6 in the above output), and for each one you need to find the package that pr...
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 can I convert this foreach code to Parallel.ForEach?
... |
edited Jul 26 '13 at 9:06
Contango
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answ...
How to drop into REPL (Read, Eval, Print, Loop) from Python code
...
105
You could try using the interactive option for python:
python -i program.py
This will execut...
Pandas get topmost n records within each group
...
>>> 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...
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...