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Evaluating a mathematical expression in a string
...might be possible to break out using introspection:
eval('(1).__class__.__bases__[0].__subclasses__()', {'__builtins__': None})
Evaluate arithmetic expression using ast
import ast
import operator as op
# supported operators
operators = {ast.Add: op.add, ast.Sub: op.sub, ast.Mult: op.mul,
...
Detecting endianness programmatically in a C++ program
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I don't like the method based on type punning - it will often be warned against by compiler. That's exactly what unions are for !
bool is_big_endian(void)
{
union {
uint32_t i;
char c[4];
} bint = {0x01020304};
return b...
Executing injected by innerHTML after AJAX call
...ou receive your HTML from server. Be warned: using eval can be dangerous.
Demo:
http://plnkr.co/edit/LA7OPkRfAtgOhwcAnLrl?p=preview
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Is there a way to make mv create the directory to be moved to if it doesn't exist?
...
[ -a "$dir" ] ||
mkdir -p "$dir" &&
mv "$@"
}
These based on the submission of Chris Lutz.
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Why is IntelliJ 13 IDEA so slow after upgrading from version 12?
...ntelliJ 13 after upgrading from 12.
What worked for me was editing the idea64.vmoptions in the bin folder and setting the max heap to 8 GB (was 512 MB) and the Max PermGen to at least 1GB (was 300MB).Example below:
-Xms128m
-Xmx8192m
-XX:MaxPermSize=1024m
Upon restart it was much faster.
For Int...
What are best practices for validating email addresses on iOS 2.0
...a-z0-9]+(-[a-z0-9]+)*\\.)+[a-z]{2,4}\\z";
NSString *regex2 = @"^(?=.{1,64}@.{4,64}$)(?=.{6,100}$).*";
NSPredicate *test1 = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", regex1];
NSPredicate *test2 = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", regex2];
return [test1 ev...
How can I recall the argument of the previous bash command?
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!!:n where n is the 0-based position of the argument you want.
For example:
echo 'one' 'two'
# "one two"
echo !!:2
# "two"
The ! prefix is used to access previous commands.
Other useful commands:
!$ - last argument from previous command
!^...
(-2147483648> 0) returns true in C++?
... exponent part. An integer literal may have a prefix that specifies its
base and a suffix that specifies its type.
…
The type of an integer literal is the first of the corresponding list
in which its value can be represented.
If an integer literal cannot be represented by any t...
Multi-line regex support in Vim
... for help, clarification, or responding to other answers.Making statements based on opinion; back them up with references or personal experience.To learn more, see our tips on writing great answers.
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Create an empty list in python with certain size
...ect. So unless you simply want 10 copies of the same object, use the range based variant as it creates 10 new objects. I found this distinction very important.
– Mandeep Sandhu
Apr 23 '18 at 18:29
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