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How to wait for several Futures?
...Future { println("f1!");throw new RuntimeException; 1 }
def func2 : Future[String] = Future { Thread.sleep(2000);println("f2!");"f2" }
def func3 : Future[Double] = Future { Thread.sleep(2000);println("f3!");42.0 }
val f : Future[(Int,String,Double)] = {
for {
f1 <- func1.concurrently
f...
Are memory leaks ever ok? [closed]
... you allocate ten thousand 100-byte blocks (for simplicity I'll ignore the extra memory that would be required to manage these allocations). This consumes 1MB, or 250 pages. If you then free 9000 of these blocks at random, you're left with just 1000 blocks - but they're scattered all over the place....
Difference between JSON.stringify and JSON.parse
...
JSON.stringify turns a JavaScript object into JSON text and stores that JSON text in a string, eg:
var my_object = { key_1: "some text", key_2: true, key_3: 5 };
var object_as_string = JSON.stringify(my_object);
// "{"key_1":"...
Are static class variables possible in Python?
...atic vars provided
# Check and make sure the statics var names are strings
if any(not isinstance(static,str) for static in mcls.statics[cls]):
typ = dict(zip((not isinstance(static,str) for static in mcls.statics[cls]), map(type,mcls.statics[cls])))[True].__name__
...
“is” operator behaves unexpectedly with integers
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This can be a very fast check relative to say, checking if two very long strings are equal in value. But since it applies to the uniqueness of the object, we thus have limited use-cases for it. In fact, we mostly want to use it to check for None, which is a singleton (a sole instance existing in o...
StringIO in Python3
I am using Python 3.2.1 and I can't import the StringIO module. I use
io.StringIO and it works, but I can't use it with numpy 's genfromtxt like this:
...
Get ID of last inserted document in a mongoDB w/ Java driver
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In MongoTemplate.class has a method
protected <T> void doInsert(String collectionName, T objectToSave, MongoWriter<T> writer) {
assertUpdateableIdIfNotSet(objectToSave);
initializeVersionProperty(objectToSave);
maybeEmitEvent(new BeforeConvertEvent<T>(objectToSa...
Convert two lists into a dictionary
...
dict([(k, v) for k, v in zip(keys, values)])
In the first two cases, an extra layer of non-operative (thus unnecessary) computation is placed over the zip iterable, and in the case of the list comprehension, an extra list is unnecessarily created. I would expect all of them to be less performant,...
How to determine a Python variable's type?
... whole list of information about the object including the type and the doc string for the type.
e.g.
In [9]: var = 123
In [10]: var?
Type: int
Base Class: <type 'int'>
String Form: 123
Namespace: Interactive
Docstring:
int(x[, base]) -> integer
Convert a string or number ...
How to put multiple statements in one line?
...t I just want the code to continue running ... for instance, to check if a string can be an integer try: int(string) ... If it can't, then just continue to the next line, no need for an exception. I see what you're saying, but is there any other way that can accommodate for this type of checking/err...