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How to remove all callbacks from a Handler?
I have a Handler from my sub-Activity that was called by the main Activity . This Handler is used by sub-classes to postDelay some Runnables, and I can't manage them. Now, in the onStop event, I need to remove them before finishing the Activity (somehow I called finish() , but it still call ...
Notification click: activity already open
I have an application with notifications that open a certain activity if I click them. I want that, if I click the notification and the activity is already opened, it's not started again, but just brought to front.
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ActiveRecord: size vs count
In Rails, you can find the number of records using both Model.size and Model.count . If you're dealing with more complex queries is there any advantage to using one method over the other? How are they different?
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What is a semaphore?
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Think of semaphores as bouncers at a nightclub. There are a dedicated number of people that are allowed in the club at once. If the club is full no one is allowed to enter, but as soon as one person leaves another person might enter.
It's simply a way to limit the number of consumers for...
Converting JSON String to Dictionary Not List
...nside, so when you read it in you get a list with a dictionary inside. You can access your dictionary by accessing item 0 in the list, as shown below:
json1_data = json.loads(json1_str)[0]
Now you can access the data stored in datapoints just as you were expecting:
datapoints = json1_data['datap...
Using awk to remove the Byte-order mark
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FF FE | UTF-16, little-endian
EF BB BF | UTF-8
Thus, you can see how \xef\xbb\xbf corresponds to EF BB BF UTF-8 BOM bytes from the above table.
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parseInt vs unary plus, when to use which?
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#Please see this answer for a more complete set of cases
Well, here are a few differences I know of:
An empty string "" evaluates to a 0, while parseInt evaluates it to NaN. IMO, a blank string should be a NaN.
+'' === 0; //true
isNaN(parseInt('',10)); //...
Efficient way to apply multiple filters to pandas DataFrame or Series
... return op(x[col],n)
In [15]: def f(x, *b):
return x[(np.logical_and(*b))]
In [16]: b1 = b(df, 'col1', ge, 1)
In [17]: b2 = b(df, 'col1', le, 1)
In [18]: f(df, b1, b2)
Out[18]:
col1 col2
1 1 11
Update: pandas 0.13 has a query method for these kind of use cases, assumin...
What is the difference between RegExp’s exec() function and String’s match() function?
...array form.
}
// No more matches.
String.match does this for you and discards the captured groups.
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Does the JVM prevent tail call optimizations?
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This post: Recursion or Iteration? might help.
In short, tail call optimization is hard to do in the JVM because of the security model and the need to always have a stack trace available. These requirements could in theory be supported, but it would probably require a new bytecode (see ...