大约有 44,000 项符合查询结果（耗时：0.0307秒） [XML]
How to list all installed packages and their versions in Python?
...ay of including the version ... sometimes its Package.version() or package.__version__ or package.ver or any number of other possibilities
– Joran Beasley
Oct 17 '12 at 18:16
...
How to limit the maximum value of a numeric field in a Django model?
...go.db import models
class IntegerRangeField(models.IntegerField):
def __init__(self, verbose_name=None, name=None, min_value=None, max_value=None, **kwargs):
self.min_value, self.max_value = min_value, max_value
models.IntegerField.__init__(self, verbose_name, name, **kwargs)
...
Pythonic way to combine FOR loop and IF statement
...>>> xyz = [0, 12, 4, 6, 242, 7, 9]
>>>
>>> known_things = sorted(set(a.iterkeys()).intersection(xyz))
>>> unknown_things = sorted(set(xyz).difference(a.iterkeys()))
>>>
>>> for thing in known_things:
... print 'I know about', a[thing]
...
I k...
Implement touch using Python?
...is will create a file.txt at the path.
--
Path.touch(mode=0o777, exist_ok=True)
Create a file at this given path. If mode is given, it is combined with the process’ umask value to determine the file mode and access flags. If the file already exists, the function succeeds if exist_ok is t...
Creating an abstract class in Objective-C
... format:@"You must override %@ in a subclass", NSStringFromSelector(_cmd)];
If your method returns a value, it's a bit easier to use
@throw [NSException exceptionWithName:NSInternalInconsistencyException
reason:[NSString stringWithFormat:@"You must override %...
Case insensitive searching in Oracle
... allows to fine-tune the behaviour of string comparisons by setting the NLS_COMP and NLS_SORT session parameters:
SQL> SET HEADING OFF
SQL> SELECT *
2 FROM NLS_SESSION_PARAMETERS
3 WHERE PARAMETER IN ('NLS_COMP', 'NLS_SORT');
NLS_SORT
BINARY
NLS_COMP
BINARY
SQL>
SQL> SELECT CA...
Dashed line border around UIView
...nother method if you like sublayers. In your custom view's init, put this (_border is an ivar):
_border = [CAShapeLayer layer];
_border.strokeColor = [UIColor colorWithRed:67/255.0f green:37/255.0f blue:83/255.0f alpha:1].CGColor;
_border.fillColor = nil;
_border.lineDashPattern = @[@4, @2];
[self....
Checking a Python module version at runtime
...rmation for the module (usually something like module.VERSION or module.__version__ ), however some do not.
7 Answers
...
How to remove from a map while iterating it?
...begin(); it != m.cend() /* not hoisted */; /* no increment */)
{
if (must_delete)
{
m.erase(it++); // or "it = m.erase(it)" since C++11
}
else
{
++it;
}
}
Note that we really want an ordinary for loop here, since we are modifying the container itself. The range-based loop sh...
round() for float in C++
...offers a simple set of rounding functions.
#include <boost/math/special_functions/round.hpp>
double a = boost::math::round(1.5); // Yields 2.0
int b = boost::math::iround(1.5); // Yields 2 as an integer
For more information, see the Boost documentation.
Edit: Since C++11, there are std::r...