大约有 40,000 项符合查询结果（耗时：0.0528秒） [XML]
Apply multiple functions to multiple groupby columns
...ame, you can use a normal function and supply a custom name to the special __name__ attribute like this:
def max_min(x):
return x.max() - x.min()
max_min.__name__ = 'Max minus Min'
df.groupby('group').agg({'a':['sum', 'max'],
'b':'mean',
'c'...
Best practices for in-app database migration for Sqlite
...t/set this variable with the following sqlite statements:
> PRAGMA user_version;
> PRAGMA user_version = 1;
When the app starts, I check the current user-version, apply any changes that are needed to bring the schema up to date, and then update the user-version. I wrap the updates in a t...
M_PI works with math.h but not with cmath in Visual Studio
... while checking through headers to see if there was anything undef'ing the _USE_MATH_DEFINES and found nothing.
So I moved the
#define _USE_MATH_DEFINES
#include <cmath>
to be the first thing in my file (I don't use PCHs so if you are you will have to have it after the #include "stdafx.h"...
Converting a view to Bitmap without displaying it in Android?
...( v.getLayoutParams().width, v.getLayoutParams().height, Bitmap.Config.ARGB_8888);
Canvas c = new Canvas(b);
v.layout(v.getLeft(), v.getTop(), v.getRight(), v.getBottom());
v.draw(c);
return b;
}
if the view wasn't displayed before the size of it will be zero. Its p...
Best way to make Django's login_required the default
...jango.conf import settings
from django.contrib.auth.decorators import login_required
class RequireLoginMiddleware(object):
"""
Middleware component that wraps the login_required decorator around
matching URL patterns. To use, add the class to MIDDLEWARE_CLASSES and
define LOGIN_REQ...
How can I print the contents of a hash in Perl?
...
Easy:
print "$_ $h{$_}\n" for (keys %h);
Elegant, but actually 30% slower (!):
while (my ($k,$v)=each %h){print "$k $v\n"}
share
|
im...
iPhone - Get Position of UIView within entire UIWindow
...ew.frame.origin toView:nil];
2014 Edit: Looking at the popularity of Matt__C's comment it seems reasonable to point out that the coordinates...
don't change when rotating the device.
always have their origin in the top left corner of the unrotated screen.
are window coordinates: The coordinate s...
Semantic Issue: Property's synthesized getter follows Cocoa naming convention for returning 'owned'
...gs to the none method family as opposed to the new method family:
#ifndef __has_attribute
#define __has_attribute(x) 0 // Compatibility with non-clang compilers
#endif
#if __has_attribute(objc_method_family)
#define BV_OBJC_METHOD_FAMILY_NONE __attribute__((objc_method_family(none)))
#else
#defin...
Request is not available in this context
...ted mode: Request is not available in this context exception in Application_Start:
The “Request is not available in this
context” exception is one of the more
common errors you may receive on when
moving ASP.NET applications to
Integrated mode on IIS 7.0. This
exception happens in...
What's Mongoose error Cast to ObjectId failed for value XXX at path “_id”?
...ng a request to /customers/41224d776a326fb40f000001 and a document with _id 41224d776a326fb40f000001 does not exist, doc is null and I'm returning a 404 :
...