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'is' versus try cast with null check
...actually happens below the belt. Take a look at this example:
object o = "test";
if (o is string)
{
var x = (string) o;
}
This translates to the following IL:
IL_0000: nop
IL_0001: ldstr "test"
IL_0006: stloc.0 // o
IL_0007: ldloc.0 // o
IL_0008: isinst Syste...
Most efficient way to remove special characters from string
...s if you would use it on a large string.
Edit:
I made a quick performance test, running each function a million times with a 24 character string. These are the results:
Original function: 54.5 ms.
My suggested change: 47.1 ms.
Mine with setting StringBuilder capacity: 43.3 ms.
Regular expression: ...
correct way to define class variables in Python [duplicate]
...e explains the difference between the styles:
james@bodacious-wired:~$cat test.py
#!/usr/bin/env python
class MyClass:
element1 = "Hello"
def __init__(self):
self.element2 = "World"
obj = MyClass()
print dir(MyClass)
print "--"
print dir(obj)
print "--"
print obj.element1
prin...
Get a filtered list of files in a directory
...ls.py
./apps/diaries/actions.py
./apps/diaries/querysets.py
./apps/library/tests/test_forms.py
./apps/library/migrations/0001_initial.py
./apps/polls/views.py
./apps/polls/formsets.py
./apps/polls/reports.py
./apps/polls/admin.py
Solution 3 - use "pathlib"
# lookup in current dir
path_ = pathlib....
Is there any difference between “foo is None” and “foo == None”?
...me as:
if x is not None:
# do something
The former is a boolean value test and can evaluate to false in different contexts. There are a number of things that represent false in a boolean value tests for example empty containers, boolean values. None also evaluates to false in this situation but...
Open a URL in a new tab (and not a new window)
...the default user preference in most browsers is for new tabs, so a trivial test on a browser where that preference hasn't been changed will not demonstrate this.)
CSS3 proposed target-new, but the specification was abandoned.
The reverse is not true; by specifying dimensions for the window in the ...
Why does this go into an infinite loop?
...
if you make a test, you can see that it first increments, and later attributes. So it should not attribute zero.
– Tom Brito
Sep 30 '10 at 14:16
...
How to get the caller's method name in the called method?
...
@ankostis do you have some test code to prove that?
– anatoly techtonik
Dec 15 '16 at 16:17
1
...
How to create module-wide variables in Python? [duplicate]
..._ # add this line!
if __DBNAME__ is None: # see notes below; explicit test for None
__DBNAME__ = name
else:
raise RuntimeError("Database name has already been set.")
By the way, for this example, the simple if not __DBNAME__ test is adequate, because any string value other...
Run function from the command line
... That's true, but I wouldn't recommend that solution beyond test purposes
– Wolph
Apr 26 '18 at 20:12
@...