大约有 40,000 项符合查询结果（耗时：0.0408秒） [XML]
What is the most pythonic way to check if an object is a number?
...: 0 + x
except TypeError: canadd=False
else: canadd=True
The presence of __add__ per se tells you nothing useful, since e.g all sequences have it for the purpose of concatenation with other sequences. This check is equivalent to the definition "a number is something such that a sequence of such t...
What is your favorite C programming trick? [closed]
...moving pointless variables
{
int yes=1;
setsockopt(yourSocket, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(int));
}
becomes
setsockopt(yourSocket, SOL_SOCKET, SO_REUSEADDR, (int[]){1}, sizeof(int));
Passing a Variable Amount of Arguments
void func(type* values) {
while(*values) {
...
warning about too many open figures
...) will remove a specific figure instance from the pylab state machine (plt._pylab_helpers.Gcf) and allow it to be garbage collected.
share
|
improve this answer
|
follow
...
Class method differences in Python: bound, unbound and static
... and unbound methods.
Basically, a call to a member function (like method_one), a bound function
a_test.method_one()
is translated to
Test.method_one(a_test)
i.e. a call to an unbound method. Because of that, a call to your version of method_two will fail with a TypeError
>>> a_tes...
Using OR in SQLAlchemy
...
From the tutorial:
from sqlalchemy import or_
filter(or_(User.name == 'ed', User.name == 'wendy'))
share
|
improve this answer
|
follow
...
What is a “callable”?
...allable is anything that can be called.
The built-in callable (PyCallable_Check in objects.c) checks if the argument is either:
an instance of a class with a __call__ method or
is of a type that has a non null tp_call (c struct) member which indicates callability otherwise (such as in functions,...
Placeholder in UITextView
...uble.
UIPlaceHolderTextView.h:
#import <Foundation/Foundation.h>
IB_DESIGNABLE
@interface UIPlaceHolderTextView : UITextView
@property (nonatomic, retain) IBInspectable NSString *placeholder;
@property (nonatomic, retain) IBInspectable UIColor *placeholderColor;
-(void)textChanged:(NSNotif...
What is a good pattern for using a Global Mutex in C#?
...e : IDisposable
{
//edit by user "jitbit" - renamed private fields to "_"
public bool _hasHandle = false;
Mutex _mutex;
private void InitMutex()
{
string appGuid = ((GuidAttribute)Assembly.GetExecutingAssembly().GetCustomAttributes(typeof(GuidAttribute), false).GetValue(...
What is the documents directory (NSDocumentDirectory)?
...lowing tech note: https://developer.apple.com/library/ios/technotes/tn2406/_index.html
The Apple sanctioned way (from the link above) is as follows:
// Returns the URL to the application's Documents directory.
- (NSURL *)applicationDocumentsDirectory
{
return [[[NSFileManager defaultManager] U...
Cannot kill Python script with Ctrl-C
...
Looks like in python3 you can pass daemon=True to Thread.__init__
– Ryan Haining
Aug 14 '18 at 0:57
|
show 3 more comments...