大约有 40,000 项符合查询结果（耗时：0.1132秒） [XML]
Map over object preserving keys
...
With Underscore
Underscore provides a function _.mapObject to map the values and preserve the keys.
_.mapObject({ one: 1, two: 2, three: 3 }, function (v) { return v * 3; });
// => { one: 3, two: 6, three: 9 }
DEMO
With Lodash
Lodash provides a function _.mapVa...
How to serialize a TimeSpan to XML
... this:
[XmlIgnore]
public TimeSpan TimeSinceLastEvent
{
get { return m_TimeSinceLastEvent; }
set { m_TimeSinceLastEvent = value; }
}
// XmlSerializer does not support TimeSpan, so use this property for
// serialization instead.
[Browsable(false)]
[XmlElement(DataType="duration", ElementNa...
Rails: confused about syntax for passing locals to partials
...s. However, in that subsequent call, it actually assigns :locals => your_locals_argument, which in this case is the entire :locals => {locals hash}, instead of just {locals hash}; i.e. you end up with :locals => {:locals => {locals hash}}, rather than :locals => {locals hash}.
So my ...
surface plots in matplotlib
...a surface.
Here's a smooth surface example:
import numpy as np
from mpl_toolkits.mplot3d import Axes3D
# Axes3D import has side effects, it enables using projection='3d' in add_subplot
import matplotlib.pyplot as plt
import random
def fun(x, y):
return x**2 + y
fig = plt.figure()
ax = fi...
How much is the overhead of smart pointers compared to normal pointers in C++?
...
std::unique_ptr has memory overhead only if you provide it with some non-trivial deleter.
std::shared_ptr always has memory overhead for reference counter, though it is very small.
std::unique_ptr has time overhead only during constru...
Define make variable at rule execution time
...te a unique variable, you could do the following:
out.tar :
$(eval $@_TMP := $(shell mktemp -d))
@echo hi $($@_TMP)/hi.txt
tar -C $($@_TMP) cf $@ .
rm -rf $($@_TMP)
This would prepend the name of the target (out.tar, in this case) to the variable, producing a variable with the na...
Difference between staticmethod and classmethod
... code will help: Notice the difference in the call signatures of foo, class_foo and static_foo:
class A(object):
def foo(self, x):
print "executing foo(%s, %s)" % (self, x)
@classmethod
def class_foo(cls, x):
print "executing class_foo(%s, %s)" % (cls, x)
@staticme...
Using pickle.dump - TypeError: must be str, not bytes
..., that's why you are here.
import pickle
class MyUser(object):
def __init__(self,name):
self.name = name
user = MyUser('Peter')
print("Before serialization: ")
print(user.name)
print("------------")
serialized = pickle.dumps(user)
filename = 'serialized.native'
with open(filename,...
Do declared properties require a corresponding instance variable?
...String *name;
it will generate synthesizing code as
@synthesize name = _name;
and you can access instance variable using _name
it is similar to declare
NSString* _name
but if you declare read-only property it like
@property (nonatomic, strong, readonly) NSString *name;
it will generate ...
What is the most efficient way to store a list in the Django models?
...
See docs.djangoproject.com/en/3.0/topics/db/examples/many_to_one
– Jon Ison
Jul 2 at 9:42
...