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Which method performs better: .Any() vs .Count() > 0?
...le<T> sequence.
For just IEnumerable<T>, then Any() will generally be quicker, as it only has to look at one iteration. However, note that the LINQ-to-Objects implementation of Count() does check for ICollection<T> (using .Count as an optimisation) - so if your underlying data-sou...
Capturing Groups From a Grep RegEx
...egex="[0-9]+_([a-z]+)_[0-9a-z]*"
for f in $files # unquoted in order to allow the glob to expand
do
if [[ $f =~ $regex ]]
then
name="${BASH_REMATCH[1]}"
echo "${name}.jpg" # concatenate strings
name="${name}.jpg" # same thing stored in a variable
else
...
Performance difference for control structures 'for' and 'foreach' in C#
...t will depend on whether you're doing any real work in the loop. In almost all cases, the difference to performance won't be significant, but the difference to readability favours the foreach loop.
I'd personally use LINQ to avoid the "if" too:
foreach (var item in list.Where(condition))
{
}
EDI...
Does python have an equivalent to Java Class.forName()?
...takes a fully qualified class name and returns the class, however you have all the pieces needed to build that, and you can connect them together.
One bit of advice though: don't try to program in Java style when you're in python.
If you can explain what is it that you're trying to do, maybe we ca...
__getattr__ on a module
...
A while ago, Guido declared that all special method lookups on
new-style classes bypass __getattr__ and __getattribute__. Dunder methods had previously worked on modules - you could, for example, use a module as a context manager simply by defining __enter__...
Difference between except: and except Exception as e: in Python
... print e.message, e.args
...
>>> catch()
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "<stdin>", line 3, in catch
BaseException
Which a bare except does:
>>> def catch():
... try:
... raise BaseException()
... ...
What are the mechanics of short string optimization in libc++?
...ver, I would like to know in more detail how it works in practice, specifically in the libc++ implementation:
2 Answers
...
Difference between Pragma and Cache-Control headers?
... Cache-Control: no-cache has the same meaning for requests but is actually also defined for responses, meaning "If you want to use a cached copy of this in future, you must first check with me that it is up-to-date (i.e. perform revalidation)".
– clime
Mar...
How do I create a constant in Python?
.... This is the closest equivalent to Java's final. However, it does not actually prevent reassignment:
from typing import Final
a: Final = 1
# Executes fine, but mypy will report an error if you run mypy on this:
a = 2
sha...
Why is exception.printStackTrace() considered bad practice?
...archiving the existing contents of the file/device.
or the file/device actually discards all data written to it, as is the case of /dev/null.
Inferring from the above, invoking Throwable.printStackTrace() constitutes valid (not good/great) exception handling behavior, only
if you do not have Sy...