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Handling specific errors in JavaScript (think exceptions)
...they also explain how to make it conform, though it's not as succint. Basically same as above, but using instanceOf. Check here
– Bart
Oct 20 '15 at 8:58
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MySQL Cannot drop index needed in a foreign key constraint
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You have to drop the foreign key. Foreign keys in MySQL automatically create an index on the table (There was a SO Question on the topic).
ALTER TABLE mytable DROP FOREIGN KEY mytable_ibfk_1 ;
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C++ map access discards qualifiers (const)
...k up a key without modifying the map.
find() returns an iterator, or const_iterator to an std::pair containing both the key (.first) and the value (.second).
In C++11, you could also use at() for std::map. If element doesn't exist the function throws a std::out_of_range exception, in contrast to o...
How do I iterate over an NSArray?
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The generally-preferred code for 10.5+/iOS.
for (id object in array) {
// do something with object
}
This construct is used to enumerate objects in a collection which conforms to the NSFastEnumeration protocol. This approach ha...
How to check if an object is a list or tuple (but not string)?
...quence; otherwise, if it is indexable or iterable, it's a sequence:
def is_sequence(arg):
return (not hasattr(arg, "strip") and
hasattr(arg, "__getitem__") or
hasattr(arg, "__iter__"))
def srepr(arg):
if is_sequence(arg):
return '<' + ", ".join(srepr(x) f...
How to make a phone call in android and come back to my activity when the call is done?
...ener actions to wait for a the call to start (wait until changed from PHONE_STATE_OFFHOOK to PHONE_STATE_IDLE again) and then write some code to bring your app back up on the IDLE state.
you may need to run the listener in a service to ensure it stays up and your app is restarted. some example c...
Python unittests in Jenkins?
...ittest.TestCase):
@unittest.skip("demonstrating skipping")
def test_skipped(self):
self.fail("shouldn't happen")
def test_pass(self):
self.assertEqual(10, 7 + 3)
def test_fail(self):
self.assertEqual(11, 7 + 3)
JUnit with pytest
run the tests with:
py.te...
How do I add a path to PYTHONPATH in virtualenv
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You can usually avoid having to do anything with PYTHONPATH by using .pth files. Just put a file with a .pth extension (any basename works) in your virtualenv's site-packages folder, e.g. lib\python2.7\site-packages, with the absolute p...
How can I return two values from a function in Python?
... two values, but you can return a tuple or a list and unpack it after the call:
def select_choice():
...
return i, card # or [i, card]
my_i, my_card = select_choice()
On line return i, card i, card means creating a tuple. You can also use parenthesis like return (i, card), but tuples ar...
Easy idiomatic way to define Ordering for a simple case class
...[...] to Ordered[TupleN[...]] provided an implicit Ordering[TN] exists for all elements T1, ..., TN of the tuple, which should always be the case because it makes no sense to sort on a data type with no Ordering.
The implicit ordering for Tuples is your go-to for any sorting scenario involving a co...