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Why does ++[[]][+[]]+[+[]] return the string “10”?
...array ([]). Due to references it's wrong to say [[]][0] === [], but let's call the inner array A to avoid the wrong notation.
++ before its operand means “increment by one and return the incremented result”. So ++[[]][0] is equivalent to Number(A) + 1 (or +A + 1).
Again, we can simplify the me...
Open file in a relative location in Python
...n a subdirectory beneath where the script is actually located, you can use __file__ to help you out here. __file__ is the full path to where the script you are running is located.
So you can fiddle with something like this:
import os
script_dir = os.path.dirname(__file__) #<-- absolute dir the...
How do I export UIImage array as a movie?
...riter has an input of type AVAssetWriterInput, which in turn has a method called appendSampleBuffer: that lets you add individual frames to a video stream. Essentially you’ll have to:
1) Wire the writer:
NSError *error = nil;
AVAssetWriter *videoWriter = [[AVAssetWriter alloc] initWithURL:
[...
Delete multiple objects in django
...sing a webpage. There is no category to select from so I can't delete from all of them like that. Do I have to implement my own delete form and process it in django or does django have a way to already do this? As its implemented in the admin interface.
...
Accessing last x characters of a string in Bash
... line:
$ foo=1234567890
$ echo $foo | grep -o ...$
890
To make it optionally get the 1 to 3 last chars, in case of strings with less than 3 chars, you can use egrep with this regex:
$ echo a | egrep -o '.{1,3}$'
a
$ echo ab | egrep -o '.{1,3}$'
ab
$ echo abc | egrep -o '.{1,3}$'
abc
$ echo abcd ...
Pandas percentage of total with groupby
... is a table of some kind, so 100 * x doesn't intuitively make sense (especially when some of the cells contain strings like AZ, ...).
– dhardy
Feb 6 '15 at 9:42
6
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SQL Server Management Studio SSMS tries to “save to file” instead of execute on F5
...
Ah ha! ctrl + shift + F (which is global search in VS2008) puts me in that mode. Thanks!
– MatthewMartin
Aug 4 '09 at 14:43
...
Rename specific column(s) in pandas
I've got a dataframe called data . How would I rename the only one column header? For example gdp to log(gdp) ?
5 Answe...
How do I activate a virtualenv inside PyCharm's terminal?
...with multiple projects, each which might have a different virtualenv, I'd call the ".pycharmrc" file something different, and perhaps put it into the env directory itself. ~/pycharmenv/bin/terminalactivate sounds like a good option.
– Chris Cogdon
Mar 10 '14 at...
How to change field name in Django REST Framework
...get_alternate_name(self, obj):
return obj.alternate_name
Additionally, you can use serializers.CharField with source attribute:
class ParkSerializer(serializers.ModelSerializer):
location = serializers.CharField(source='other_fields')
class Meta:
model = Park
fiel...