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ViewPager and fragments — what's the right way to store fragment's state?
... you are using FragmentStatePagerAdapter). This is controlled by ViewPager.setOffscreenPageLimit(int). Because of this, directly calling methods on the fragments outside of the adapter is not guaranteed to be valid, because they may not even be alive.
To cut a long story short, your solution to us...
How do I rename a column in a SQLite database table?
...he NOT NULL constraint, or change the data type, you can use the following set of commands:
Note: These commands have the potential to corrupt your database, so make sure you have a backup
PRAGMA writable_schema = 1;
UPDATE SQLITE_MASTER SET SQL = 'CREATE TABLE BOOKS ( title TEXT NOT NULL, publica...
Change type of varchar field to integer: “cannot be cast automatically to type integer”
...ow update command (if not above alter table will fail):
UPDATE the_table SET col_name = replace(col_name, 'some_string', '');
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Shuffling a list of objects
... range(555)
b = random.sample(a, len(a))
print "no duplicates:", a == list(set(b))
try:
random.sample(a, len(a) + 1)
except ValueError as e:
print "Nope!", e
# print: no duplicates: True
# print: Nope! sample larger than population
...
How to run Django's test database only in memory?
...
If you set your database engine to sqlite3 when you run your tests, Django will use a in-memory database.
I'm using code like this in my settings.py to set the engine to sqlite when running my tests:
if 'test' in sys.argv:
DAT...
java.lang.UnsupportedClassVersionError: Bad version number in .class file?
..., and only needs a 1.5 JRE to compile 1.6 classes.
It may be weird, and a setting needs to be unchecked to allow this, but I just managed to do it.
For the project in question, check the Project Properties (usually Alt+Enter), Java Compiler section. Here's an image of a project configured to compi...
Convert data.frame column format from character to factor
...
Hi welcome to the world of R.
mtcars #look at this built in data set
str(mtcars) #allows you to see the classes of the variables (all numeric)
#one approach it to index with the $ sign and the as.factor function
mtcars$am <- as.factor(mtcars$am)
#another approach
mtcars[, 'cyl'] <- ...
What is the difference between object keys with quotes and without quotes?
..., and non-quoted words are turned into functions. For example, "size" will set the size attribute of the object, and size (no quotes), will call the size() function on the object. See jQuery(), near the bottom:
While the second argument is convenient, its flexibility can lead to unintended conse...
getSupportActionBar from inside of Fragment ActionBarCompat
...portActionBar().
((AppCompatActivity)getActivity()).getSupportActionBar().setSubtitle(R.string.subtitle);
You do need the cast. It's not poor design, it's backwards compatibility.
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