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Python - Create a list with initial capacity
...to 300x slower than other languages due to Python features like decorators etc (https://wiki.python.org/moin/PythonSpeed/PerformanceTips#Data_Aggregation#Data_Aggregation).
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What's wrong with nullable columns in composite primary keys?
... comparisons. This can be a source of subtle bugs when sorting, comparing, etc.
Postgres assumes you're an adult and can make this decision for yourself. Oracle and DB2 assume you didn't realize you were doing something silly and throw an error. This is usually the right thing, but not always -- yo...
source of historical stock data [closed]
... as two different symbols, or stock splits are not properly accounted for, etc. And then you realize that historical dividend data is need as well and so you start running in circles, patching data together from 100 different data sources and so on. So to start with a "discount" data feed will do, b...
In Functional Programming, what is a functor?
...bananas, and we map the same function, we now would have a tree of apples. Etc. tree and list are two Functors here.
– Qqwy
Jun 19 '16 at 21:34
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How to securely store access token and secret in Android?
I am going to use oAuth to fetch mails and contacts from google. I don't want to ask the user each time to log in to obtain an access token and secret. From what I understood, I need to store them with my application either in a database or SharedPreferences . But I am a bit worried about security ...
Is there a difference between copy initialization and direct initialization?
...ed temporary. Any members of c1 that have pod-type (or members of members, etc., etc.) may not be initialized if the user supplied default constructors (if any) do not explicitly initialize them. For c2, it depends on whether there is a user supplied copy constructor and whether that appropriately i...
Change column type from string to float in Pandas
... data type you can give your datatype .what do you want like str,float,int etc.
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How to get current CPU and RAM usage in Python?
...d way of getting current system status (current CPU, RAM, free disk space, etc.) in Python? Bonus points for *nix and Windows platforms.
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REST API 404: Bad URI, or Missing Resource?
...ifference, but that doesn't imply that an empty string is an error. To stretch the analogy: You could have a method String getName() that has an implementation like this: return this.name == null ? "" : this.name. That's not incorrect unless you want the client to know that this.name is null.
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Qt events and signal/slots
...e the button should function like a normal QPushButton (it can be clicked, etc). In Qt this is done by creating your own little reusable "component" (subclass of QPushButton), which reimplements QWidget::keyPressEvent. Pseudocode:
class NumericButton extends QPushButton
private void addToNumber...