大约有 47,000 项符合查询结果（耗时：0.0784秒） [XML]
Hashing a dictionary?
...
@Ceaser That won't work because tuple implies ordering but dict items are unordered. frozenset is better.
– Antimony
Jul 30 '12 at 11:55
28
...
How do you serialize a model instance in Django?
...h trying to serialize a single object, not a list of objects. That way, in order to get rid of different hacks, just use Django's model_to_dict (if I'm not mistaken, serializers.serialize() relies on it, too):
from django.forms.models import model_to_dict
# assuming obj is your model instance
dic...
Meaning of tilde in Linux bash (not home directory)
...tion is usually controlled by NSS; so by default values are pulled out of /etc/passwd, though it can be configured to retrieve the information using any source desired, such as NIS, LDAP or an SQL database.
Tilde expansion is more than home directory lookup. Here's a summary:
~ $HOME
~f...
Can you do greater than comparison on a date in a Rails 3 search?
...er.id, :notetype => p[:note_type]).
where("date > ?", p[:date]).
order('date ASC, created_at ASC')
or you can also convert everything into the SQL notation
Note.
where("user_id = ? AND notetype = ? AND date > ?", current_user.id, p[:note_type], p[:date]).
order('date ASC, created...
What are the most common SQL anti-patterns? [closed]
...t *, you get whatever is in the table. Those columns may change names and order. Client code frequently relies on names and order. Every 6 months I'm asked how to preserve column order when modifying a table. If the rule was followed it wouldn't matter.
– Amy B
...
Getting error: Peer authentication failed for user “postgres”, when trying to get pgsql working with
...
The problem is still your pg_hba.conf file (/etc/postgresql/9.1/main/pg_hba.conf*).
This line:
local all postgres peer
Should be:
local all postgres md5
* If you can't fin...
how to split the ng-repeat data with three columns using bootstrap
...rent.$index*row.length)+$index+1}}. {{item}}
</div>
</div>
Order items vertically
1 4
2 5
3 6
Regarding vertical columns (list top to bottom) rather than horizontal (left to right), the exact implementation depends on the desired semantics. Lists that divide up unevenly can be ...
My Understanding of HTTP Polling, Long Polling, HTTP Streaming and WebSockets
..., long poll, streaming.
Bi-direcitonal: WebSockets, plugin networking
In order of increasing latency (approximate):
WebSockets
Plugin networking
HTTP streaming
HTTP long-poll
HTTP polling
CORS (cross-origin support):
WebSockets: yes
Plugin networking: Flash via policy request (not sure about...
Cookies vs. sessions
...
Short answer
Rules ordered by priority:
Rule 1. Never trust user input : cookies are not safe. Use sessions for sensitive data.
Rule 2. If persistent data must remain when the user closes the browser, use cookies.
Rule 3. If persistent data d...
Get the first key name of a javascript object [duplicate]
..." key in a hash (Javascript calls them objects). They are fundamentally unordered. Do you mean just choose any single key:
for (var k in ahash) {
break
}
// k is a key in ahash.
share
|
imp...