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What is the best way to find the users home directory in Java?
... looking for a snippet of code that can accomplish this for all platforms, and a way to detect the platform.
9 Answers
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Detect if a NumPy array contains at least one non-numeric value?
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This should be faster than iterating and will work regardless of shape.
numpy.isnan(myarray).any()
Edit: 30x faster:
import timeit
s = 'import numpy;a = numpy.arange(10000.).reshape((100,100));a[10,10]=numpy.nan'
ms = [
'numpy.isnan(a).any()',
'any(n...
Filter rows which contain a certain string
...mail in the comments above. You can use regular expressions for the second and subsequent arguments of filter like this:
dplyr::filter(df, !grepl("RTB",TrackingPixel))
Since you have not provided the original data, I will add a toy example using the mtcars data set. Imagine you are only intereste...
How to convert a byte array to a hex string in Java?
I have a byte array filled with hex numbers and printing it the easy way is pretty pointless because there are many unprintable elements. What I need is the exact hexcode in the form of: 3a5f771c
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delegate keyword vs. lambda notation
...delegates (such as System.Func) uses System.Linq.Enumerable. Linq to SQL (and anything else) with expressions uses System.Linq.Queryable. Check out the parameters on those methods.
An Explanation from ScottGu. In a nutshell, Linq in-memory will produce some anonymous methods to resolve your query...
Why do we need C Unions?
...s are often used to convert between the binary representations of integers and floats:
union
{
int i;
float f;
} u;
// Convert floating-point bits to integer:
u.f = 3.14159f;
printf("As integer: %08x\n", u.i);
Although this is technically undefined behavior according to the C standard (you'r...
SLF4J: Class path contains multiple SLF4J bindings
... to find out how log4j is getting on your path run mvn dependency:tree and comb through, then add the snippet above to that dependency in your pom.xml
– cyber-monk
Sep 15 '15 at 15:11
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In Perl, how can I read an entire file into a string?
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Add:
local $/;
before reading from the file handle. See How can I read in an entire file all at once?, or
$ perldoc -q "entire file"
See Variables related to filehandles in perldoc perlvar and perldoc -f local.
Incidentally, if you can put your script on the server,...
How can I read a large text file line by line using Java?
...o ensure the #close method is called on it, otherwise the underlying file handle is never closed until GC does it much later.
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Ruby, remove last N characters from a string?
... 2.5 you can use delete_suffix or delete_suffix! to achieve this in a fast and readable manner.
The docs on the methods are here.
If you know what the suffix is, this is idiomatic (and I'd argue, even more readable than other answers here):
'abc123'.delete_suffix('123') # => "abc"
'abc123'...