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JSON serialization of Google App Engine models
...add=True)
album = db.ReferenceProperty(Album, collection_name='photo')
from django.utils import simplejson
from google.appengine.ext import webapp
class PhotoHandler(webapp.RequestHandler):
def get(self):
photos = Photo.all()
self.response.out.write(simplejson.dumps([p.to_dict() ...
Difference between “git add -A” and “git add .”
... <path>" now, so that
"git add dir/" will notice paths you removed from the directory and
record the removal.
In older versions of Git, "git add <path>" ignored removals.
You can say "git add --ignore-removal <path>" to
add only added or modified paths in <path>...
Python “extend” for a dictionary
...arn what **basket_two (the **) means here.
In case of conflict, the items from basket_two will override the ones from basket_one. As one-liners go, this is pretty readable and transparent, and I have no compunction against using it any time a dict that's a mix of two others comes in handy (any rea...
What's the difference between emulation and simulation? [duplicate]
...fically, an emulator attempts to duplicate the entire behavior of a device from an external viewpoint. It may or may not need to duplicate the inner workings of a device to accomplish that. A simulation attempts to duplicate a specific subset of a device's behavior.
– Jay Elsto...
How get integer value from a enum in Rails?
...
You can get the integer values for an enum from the class the enum is on:
Model.sale_infos # Pluralized version of the enum attribute name
That returns a hash like:
{ "plan_1" => 1, "plan_2" => 2 ... }
You can then use the sale_info value from an instance ...
What exactly does a jar file contain?
...ar file with a zip utility or run jar xf foo.jar you can extract the files from it, and have a look at them. Note that you don't need a jar file to run Java code - classloaders can load class data directly from the file system, or from URLs, as well as from jar files.
...
Import multiple csv files into pandas and concatenate into one DataFrame
I would like to read several csv files from a directory into pandas and concatenate them into one big DataFrame. I have not been able to figure it out though. Here is what I have so far:
...
I ran into a merge conflict. How can I abort the merge?
...ways, make sure you have no uncommitted changes before you start a merge.
From the git merge man page
git merge --abort is equivalent to git reset --merge when MERGE_HEAD is present.
MERGE_HEAD is present when a merge is in progress.
Also, regarding uncommitted changes when starting a merge:
If...
Will using goto leak variables?
... may be prone to this.)
Consider the following mechanics that prevent you from doing "bad things" with labels (which includes case labels).
1. Label scope
You can't jump across functions:
void f() {
int x = 0;
goto lol;
}
int main() {
f();
lol:
return 0;
}
// error: label 'lol' u...
When and why should I use fragments in Android applications? [duplicate]
...self the following questions:
Is the lifecycle of the fragment different from the activity's lifecycle?
If the lifecycle is different, you get better handling of the lifecycle using a fragment. For example, if you want to destroy the fragment, but not the activity. Such is the case, when you hav...