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What's the _ underscore representative of in Swift References?
...
Both answers were correct but I want to clarify a little bit more.
_ is used to modify external parameter name behavior for methods.
In Local and External Parameter Names for Methods section of the documentation, it says:
Swift gives the first parameter name in a method a local paramete...
Check if OneToOneField is None in Django
...ately, this doesn't work all the time. In case you want to work with select_related() now or in the future -- or maybe even to be sure you also handle other sorts of magic which may happen elsewhere -- you have to extend the test as follows: if hasattr(object, 'onetoonerevrelattr') and object.onetoo...
What is the command to list the available avdnames
...ators: emulator @name-of-your-emulator where emulator is under: ${ANDROID_SDK}/tools/emulator
– Dhiraj Himani
Jun 16 '17 at 11:27
...
How to make URL/Phone-clickable UILabel?
...erride var attributedText: NSAttributedString?{
didSet{
if let _attributedText = attributedText{
self.textStorage = NSTextStorage(attributedString: _attributedText)
self.layoutManager.addTextContainer(self.textContainer)
self.textStorage?.addLayoutMan...
How to search a specific value in all tables (PostgreSQL)?
...
How about dumping the contents of the database, then using grep?
$ pg_dump --data-only --inserts -U postgres your-db-name > a.tmp
$ grep United a.tmp
INSERT INTO countries VALUES ('US', 'United States');
INSERT INTO countries VALUES ('GB', 'United Kingdom');
The same utility, pg_dump, can...
Python debugging tips [closed]
...
PDB
You can use the pdb module, insert pdb.set_trace() anywhere and it will function as a breakpoint.
>>> import pdb
>>> a="a string"
>>> pdb.set_trace()
--Return--
> <stdin>(1)<module>()->None
(Pdb) p a
'a string'
(Pdb)
To...
unbound method f() must be called with fibo_ instance as first argument (got classobj instance inste
...thod() to access parent methods.
class ParentClass(object):
def method_to_call(self, arg_1):
print arg_1
class ChildClass(ParentClass):
def do_thing(self):
super(ChildClass, self).method_to_call('my arg')
...
How to call C from Swift?
... frame = CGRect(x: 10, y: 10, width: 100, height: 100)
import Darwin
for _ in 1..10 {
println(rand() % 100)
}
See Interacting with Objective-C APIs in the docs.
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Android Studio says “cannot resolve symbol” but project compiles
...e link to the compiled version of your libs. These files starts with Gradle__artifacts_*.xml (where * is the name of your libs).
So in order for Android Studio to take the latest version of your libs, you need to delete these Gradle__artifacts_*.xml files, and Android Studio will regenerate them, p...
Reading a huge .csv file
...tly over getdata() in your code:
for row in getdata(somefilename, sequence_of_criteria):
# process row
You now only hold one row in memory, instead of your thousands of lines per criterion.
yield makes a function a generator function, which means it won't do any work until you start looping ...