大约有 40,000 项符合查询结果（耗时：0.0507秒） [XML]
Best way to iterate through a Perl array
...ay elements occurs. ($_ is aliased to the element in #1, but #2 and #3 actually copy the scalars from the array.)
#5 might be similar.
In terms memory usage: They're all the same except for #5.
for (@a) is special-cased to avoid flattening the array. The loop iterates over the indexes of the array...
Why is there no xrange function in Python3?
...Some performance measurements, using timeit instead of trying to do it manually with time.
First, Apple 2.7.2 64-bit:
In [37]: %timeit collections.deque((x for x in xrange(10000000) if x%4 == 0), maxlen=0)
1 loops, best of 3: 1.05 s per loop
Now, python.org 3.3.0 64-bit:
In [83]: %timeit collec...
Difference between staticmethod and classmethod
...
Maybe a bit of example 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...
Find object in list that has attribute equal to some value (that meets any condition)
...eat solution, but how do i modify your line so that I can make x.value actually mean x.fieldMemberName where that name is stored in value? field = "name" next((x for x in test_list if x.field == value), None) so that in this case, i am actually checking against x.name, not x.field
...
How to read if a checkbox is checked in PHP?
...
this is the really good form to do this in pure simple php. but have to note that the value of a checkbox is string on when it is activated an a inexisting value if it is checked.
– Elvis Technologies
...
PHP_SELF vs PATH_INFO vs SCRIPT_NAME vs REQUEST_URI
I am building a PHP application in CodeIgniter. CodeIgniter sends all requests to the main controller: index.php . However, I don't like to see index.php in the URI. For example, http://www.example.com/faq/whatever will route to http://www.example.com/index.php/faq/whatever . I need a reliable...
Is there an IDictionary implementation that, on missing key, returns the default value instead of th
...
Indeed, that won't be efficient at all.
You could always write an extension method:
public static TValue GetValueOrDefault<TKey,TValue>
(this IDictionary<TKey, TValue> dictionary, TKey key)
{
TValue ret;
// Ignore return value
dic...
Export specific rows from a PostgreSQL table as INSERT SQL script
....5.3, and my create statement was the same as yours except create view.... All I get in the output is the usual pg_dump comments and SET statements. Not sure where I'm going wrong.
– poshest
Nov 20 '16 at 15:19
...
Circle line-segment collision detection algorithm?
... exdx + eydy - dxh - dyk ) +
ex2 + ey2 -
2exh - 2eyk + h2 + k2 - r2 = 0
Finally,
t2( _d * _d ) + 2t( _e * _d - _d * _c ) + _e * _e - 2( _e*_c ) + _c * _c - r2 = 0
*Where _d is the vector d and * is the dot product.*
And then,
t2( _d * _d ) + 2t( _d * ( _e - _c ) ) + ( _e - _c ) * ( _e - _c ) - r2 = ...
What is the purpose of std::make_pair vs the constructor of std::pair?
...
Actually, the types should be deduced at compile time without the need to specify.
– Chad
Feb 14 '12 at 1:51
...