大约有 40,000 项符合查询结果（耗时：0.0248秒） [XML]
Django Rest Framework: Dynamically return subset of fields
...verride the serializer __init__ method and set the fields attribute dynamically, based on the query params. You can access the request object throughout the context, passed to the serializer.
Here is a copy&paste from Django Rest Framework documentation example on the matter:
from rest_framew...
In a django model custom save() method, how should you identify a new object?
...
Not all models have an id attribute, i.e. a model extending another through a models.OneToOneField(OtherModel, primary_key=True). I think you need to use self.pk
– AJP
Apr 9 '13 at 10:21
...
capturing self strongly in this block is likely to lead to a retain cycle
...
Good answer, but I take small issue with you saying: “you can't refer to self or properties on self from within a block that will be strongly retained by self.” This is not strictly true. Please see my answer below. Better to say, “you must take...
Determine project root from a running node.js application
...uire.main === module
Because module provides a filename property (normally equivalent to __filename), the entry point of the current application can be obtained by checking require.main.filename.
So if you want the base directory for your app, you can do:
var path = require('path');
var appD...
What does it mean if a Python object is “subscriptable” or not?
Which types of objects fall into the domain of "subscriptable"?
6 Answers
6
...
Why does modern Perl avoid UTF-8 by default?
...?????????????????????
Set your PERL_UNICODE envariable to AS. This makes all Perl scripts decode @ARGV as UTF‑8 strings, and sets the encoding of all three of stdin, stdout, and stderr to UTF‑8. Both these are global effects, not lexical ones.
At the top of your source file (program, module, l...
How to pretty-print a numpy.array without scientific notation and with given precision?
...335 0.712]
And suppress suppresses the use of scientific notation for small numbers:
y=np.array([1.5e-10,1.5,1500])
print(y)
# [ 1.500e-10 1.500e+00 1.500e+03]
np.set_printoptions(suppress=True)
print(y)
# [ 0. 1.5 1500. ]
See the docs for set_printoptions for other options.
T...
Finding a branch point with Git?
... B. Here are three ways that I found, after a bit of tinkering:
1. visually, with gitk:
You should visually see a tree like this (as viewed from master):
or here (as viewed from topic):
in both cases, I've selected the commit that is B in my graph. Once you click on it, its full SHA is p...
How to ignore user's time zone and force Date() use specific time zone
...
A Date object's underlying value is actually in UTC. To prove this, notice that if you type new Date(0) you'll see something like: Wed Dec 31 1969 16:00:00 GMT-0800 (PST). 0 is treated as 0 in GMT, but .toString() method shows the local time.
Big note, UTC stands ...
What are “named tuples” in Python?
...
Named tuples are basically easy-to-create, lightweight object types. Named tuple instances can be referenced using object-like variable dereferencing or the standard tuple syntax. They can be used similarly to struct or other common record types...