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How can I validate a string to only allow alphanumeric characters in it?
How can I validate a string using Regular Expressions to only allow alphanumeric characters in it?
10 Answers
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How do I properly escape quotes inside HTML attributes?
...ric html entities over named entities, in that named entities do not cover all characters, while numeric entities do. The full HTML4 list is at w3.org/TR/html4/sgml/entities.html .
– atk
Oct 25 '10 at 14:42
...
Do Java arrays have a maximum size?
...ry easy to test.
In a recent HotSpot VM, the correct answer is Integer.MAX_VALUE - 5. Once you go beyond that:
public class Foo {
public static void main(String[] args) {
Object[] array = new Object[Integer.MAX_VALUE - 4];
}
}
You get:
Exception in thread "main" java.lang.OutOfMemoryEr...
Is there a way to filter network requests using Google Chrome developer tools?
... to filter out some requests using Chrome developer tools, say, filter out all image requests?
8 Answers
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What are the -Xms and -Xmx parameters when starting JVM?
...
The flag Xmx specifies the maximum memory allocation pool for a Java virtual machine (JVM), while Xms specifies the initial memory allocation pool.
This means that your JVM will be started with Xms amount of memory and will be able to use a maximum of Xmx amount of ...
PostgreSQL Autoincrement
...other integer data type, such as smallint.
Example :
CREATE SEQUENCE user_id_seq;
CREATE TABLE user (
user_id smallint NOT NULL DEFAULT nextval('user_id_seq')
);
ALTER SEQUENCE user_id_seq OWNED BY user.user_id;
Better to use your own data type, rather than user serial data type.
...
Set initial focus in an Android application
In my Android application it automatically focuses the first Button I have in my layout, giving it an orange outline. How can I set the initial focus preferably in XML, and can this be set to nothing?
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Moving average or running mean
...
UPD: more efficient solutions have been proposed by Alleo and jasaarim.
You can use np.convolve for that:
np.convolve(x, np.ones((N,))/N, mode='valid')
Explanation
The running mean is a case of the mathematical operation of convolution. For the running mean, you slide...
Find integer index of rows with NaN in pandas dataframe
...
And just in case, if you want to find the coordinates of 'nan' for all the columns instead (supposing they are all numericals), here you go:
df = pd.DataFrame([[0,1,3,4,np.nan,2],[3,5,6,np.nan,3,3]])
df
0 1 2 3 4 5
0 0 1 3 4.0 NaN 2
1 3 5 6 NaN 3.0 3
np.where(np.as...
How to fix Python indentation
...py script that you find in the Tools/scripts/ directory of your Python installation:
Change Python (.py) files to use
4-space indents and no hard tab
characters. Also trim excess spaces
and tabs from ends of lines, and
remove empty lines at the end of
files. Also ensure the last line ...