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What does the exclamation mark mean in a Haskell declaration?
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It's a strictness declaration. Basically, it means that it must be evaluated to what's called "weak head normal form" when the data structure value is created. Let's look at an example, so that we can see just what this means:
data Foo = Foo Int Int !Int !(May...
How to smooth a curve in the right way?
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I prefer a Savitzky-Golay filter. It uses least squares to regress a small window of your data onto a polynomial, then uses the polynomial to estimate the point in the center of the window. Finally the window is shifted forward by one data point and the process repeats. This continues until ever...
Kill child process when parent process is killed
...plication dies, you are still left with child processes running. What we really want is for the child processes to die as soon as the main process dies.
The solution is to use "job objects" http://msdn.microsoft.com/en-us/library/ms682409(VS.85).aspx.
The idea is to create a "job object" for your ...
Converting strings to floats in a DataFrame
...newer version of pandas (0.17 and up), you can use to_numeric function. It allows you to convert the whole dataframe or just individual columns. It also gives you an ability to select how to treat stuff that can't be converted to numeric values:
import pandas as pd
s = pd.Series(['1.0', '2', -3])
p...
Literal suffix for byte in .NET?
...e var, you can always cast the byte as in var y = (byte) 5
Although not really related, in C#7, a new binary prefix was introduced 0b, which states the number is in binary format. Still there is no suffix to make it a byte though, example:
var b = 0b1010_1011_1100_1101_1110_1111; //int
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How to convert JSON string to array
...d keys). That's what the documentation says and that's what my PHP 5.2 installation returns. Are you using a function other than the official, built-in json_decode()? What does var_dump(json_decode($str, true)); return?
– RickN
Sep 22 '11 at 15:34
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Are tuples more efficient than lists in Python?
...l be more like the tuple example above than the list example, but do you really believe that means performance will be similar?
– mzz
Jan 31 '10 at 15:21
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What are dictionary view objects?
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Dictionary views are essentially what their name says: views are simply like a window on the keys and values (or items) of a dictionary. Here is an excerpt from the official documentation for Python 3:
>>> dishes = {'eggs': 2, 'sausage': 1, ...
Received an invalid column length from the bcp client for colid 6
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Specifically, if you have any columns that are VARCHAR smaller than 4, watch out for NULL in your data getting misinterpreted as the 4char string "NULL"
– CrazyPyro
Feb 11 at 8:13
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How to get the name of enumeration value in Swift?
... on each case to return a string literal. In addition, this works automatically for any enum, even if no raw-value type is specified.
debugPrint(_:) & String(reflecting:) can be used for a fully-qualified name:
debugPrint(city)
// prints "App.City.Melbourne" (or similar, depending on the full ...