大约有 19,000 项符合查询结果（耗时：0.0418秒） [XML]
Is there a difference between “==” and “is”?
... most cases this logic is true, but it relies on the implementation of the __eq__ special method. As the docs say,
The default behavior for equality comparison (== and !=) is based on
the identity of the objects. Hence, equality comparison of instances
with the same identity results in equa...
Does C have a “foreach” loop construct?
...ave a foreach, but macros are frequently used to emulate that:
#define for_each_item(item, list) \
for(T * item = list->head; item != NULL; item = item->next)
And can be used like
for_each_item(i, processes) {
i->wakeup();
}
Iteration over an array is also possible:
#define f...
rails i18n - translating text with links inside
...
en.yml
log_in_message_html: "This is a text, with a %{href} inside."
log_in_href: "link"
login.html.erb
<p> <%= t("log_in_message_html", href: link_to(t("log_in_href"), login_path)) %> </p>
...
`staticmethod` and `abc.abstractmethod`: Will it blend?
...
class abstractstatic(staticmethod):
__slots__ = ()
def __init__(self, function):
super(abstractstatic, self).__init__(function)
function.__isabstractmethod__ = True
__isabstractmethod__ = True
class A(object):
__metaclass__ = abc.AB...
How to check if an object is a list or tuple (but not string)?
...quence; otherwise, if it is indexable or iterable, it's a sequence:
def is_sequence(arg):
return (not hasattr(arg, "strip") and
hasattr(arg, "__getitem__") or
hasattr(arg, "__iter__"))
def srepr(arg):
if is_sequence(arg):
return '<' + ", ".join(srepr(x) f...
How to find the installed pandas version
...
Check pandas.__version__:
In [76]: import pandas as pd
In [77]: pd.__version__
Out[77]: '0.12.0-933-g281dc4e'
Pandas also provides a utility function, pd.show_versions(), which reports the version of its dependencies as well:
In [53]...
What to put in a python module docstring? [closed]
...
NAME
x - This module does blah blah.
FILE
/tmp/x.py
CLASSES
__builtin__.object
Blah
class Blah(__builtin__.object)
| This class does blah blah.
|
| Data and other attributes defined here:
|
| __dict__ = <dictproxy object>
| ...
How to find the size of localStorage
...
Execute this snippet in JavaScript console (one line version):
var _lsTotal=0,_xLen,_x;for(_x in localStorage){ if(!localStorage.hasOwnProperty(_x)){continue;} _xLen= ((localStorage[_x].length + _x.length)* 2);_lsTotal+=_xLen; console.log(_x.substr(0,50)+" = "+ (_xLen/1024).toFixed(2)+" KB")...
Why does @foo.setter in Python not work for me?
...operty
def x(self):
print 'called getter'
return self._x
@x.setter
def x(self, value):
print 'called setter'
self._x = value
It works:
>>> k = testDec()
>>> k.x
called getter
Traceback (most recent call last):
File "<stdin>"...
Is there a decorator to simply cache function return values?
...
Starting from Python 3.2 there is a built-in decorator:
@functools.lru_cache(maxsize=100, typed=False)
Decorator to wrap a function with a memoizing callable that saves up to the maxsize most recent calls. It can save time when an expensive or I/O bound function is periodically called with th...