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Only read selected columns
...,Apr,May,Jun from file",
sep = "\t")
3) With the read_*-functions from the readr-package:
library(readr)
dat <- read_table("data.txt",
col_types = cols_only(Year = 'i', Jan = 'i', Feb = 'i', Mar = 'i',
Apr = 'i', May...
Virtual Memory Usage from Java under Linux, too much memory used
...6-x64/jre/lib/amd64/libjava.so
...
00007fa1f34aa000 1576K r-x-- /lib/x86_64-linux-gnu/libc-2.13.so
00007fa1f3634000 2044K ----- /lib/x86_64-linux-gnu/libc-2.13.so
00007fa1f3833000 16K r-x-- /lib/x86_64-linux-gnu/libc-2.13.so
00007fa1f3837000 4K rwx-- /lib/x86_64-linux-gnu/libc-2.13....
How to organize a node app that uses sequelize?
...e is cached after the first execution. nodejs.org/api/modules.html#modules_caching
– Casey Flynn
Mar 29 '13 at 7:17
2
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Type hinting a collection of a specified type
...ntainers.
In other words, now you can do:
from typing import List
def my_func(l: List[int]):
pass
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Getting the first character of a string with $str[0]
...ng multibyte encodings (such as UTF-8). If you want to support that, use mb_substr(). Arguably, you should always assume multibyte input these days, so this is the best option, but it will be slightly slower.
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Install a .NET windows service without InstallUtil.exe
...My Sample Service", "Service that executes something",
_InstanceID,
// System.ServiceProcess.ServiceAccount.LocalService, // this is more secure, but only available in XP and above and WS-2003 and above
System.ServiceProcess.ServiceAccount.LocalSystem, // this is req...
Method overloading in Objective-C?
...sign pattern)
Here's a simple example on how function overloading works:
__attribute__((overloadable)) float area(Circle * this)
{
return M_PI*this.radius*this.radius;
}
__attribute__((overloadable)) float area(Rectangle * this)
{
return this.w*this.h;
}
//...
//In your Obj-C methods you...
C-like structures in Python
...uct(NamedTuple):
foo: str
bar: int
baz: list
qux: User
my_item = MyStruct('foo', 0, ['baz'], User('peter'))
print(my_item) # MyStruct(foo='foo', bar=0, baz=['baz'], qux=User(name='peter'))
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Best way to iterate through a Perl array
...C instead of Perl, and no needless copying of the array elements occurs. ($_ is aliased to the element in #1, but #2 and #3 actually copy the scalars from the array.)
#5 might be similar.
In terms memory usage: They're all the same except for #5.
for (@a) is special-cased to avoid flattening the a...
multiprocessing: sharing a large read-only object between processes?
...), and Yes in 3.8 (https://docs.python.org/3/library/multiprocessing.shared_memory.html#module-multiprocessing.shared_memory)
Processes have independent memory space.
Solution 1
To make best use of a large structure with lots of workers, do this.
Write each worker as a "filter" – reads interm...