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How does Django's Meta class work?
I am using Django which allows people to add extra parameters to a class by using class Meta .
6 Answers
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List all sequences in a Postgres db 8.1 with SQL
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The following query gives names of all sequences.
SELECT c.relname FROM pg_class c WHERE c.relkind = 'S';
Typically a sequence is named as ${table}_id_seq. Simple regex pattern matching will give you the table name.
To get last value of a sequence use the ...
Difference between encoding and encryption
...ion of how text should be transformed into bytes. Similarly, HTTP does not allow all characters to be transmitted safely, so it may be necessary to encode data using base64 (uses only letters, numbers and two safe characters).
When encoding or decoding, the emphasis is placed on everyone having the...
How to resize superview to fit all subviews with autolayout?
...n a UITableViewCell (to determine row height for example) then you should call it against your cell contentView and grab the height.
Further considerations exist if you have one or more UILabel's in your view that are multiline. For these it is imperitive that the preferredMaxLayoutWidth propert...
How to write very long string that conforms with PEP8 and prevent E501
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Implicit concatenation might be the cleanest solution:
s = "this is my really, really, really, really, really, really," \
" really long string that I'd like to shorten."
Edit On reflection I agree that Todd's suggestion to use brackets rather than line continuation is better for all the reas...
How to create a zip archive of a directory in Python?
...e. The documentation tells you what functions are available, but doesn't really explain how you can use them to zip an entire directory. I think it's easiest to explain with some example code:
#!/usr/bin/env python
import os
import zipfile
def zipdir(path, ziph):
# ziph is zipfile handle
f...
Is “argv[0] = name-of-executable” an accepted standard or just a common convention?
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Guesswork (even educated guesswork) is fun but you really need to go to the standards documents to be sure. For example, ISO C11 states (my emphasis):
If the value of argc is greater than zero, the string pointed to by argv[0] represents the program name; argv[0][0] shall b...
How do I partially update an object in MongoDB so the new object will overlay / merge with the exist
...n would be that you are happy with $set, but do not want to explicitly set all fields. How would you pass in the data then?
You know you can do the following:
db.collection.update( { _id:...} , { $set: someObjectWithNewData }
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Early exit from function?
... return;
}
This will send a return value of undefined to whatever called the function.
var x = myfunction();
console.log( x ); // console shows undefined
Of course, you can specify a different return value. Whatever value is returned will be logged to the console using the above example...
Sort objects in an array alphabetically on one property of the array
... learn something new every day - localeCompare is cool and has all browser support for first arg. Not bad!
– obzenner
Jun 15 '18 at 21:34
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