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Remove Primary Key in MySQL
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Without an index, maintaining an autoincrement column becomes too expensive, that's why MySQL requires an autoincrement column to be a leftmost part of an index.
You should remove the autoincrement property before dropping th...
Compare two DataFrames and output their differences side-by-side
... isEnrolled True False
Comment None On vacation
* Note: it's important that df1 and df2 share the same index here. To overcome this ambiguity, you can ensure you only look at the shared labels using df1.index & df2.index, but I think I'll leave that as an exercise.
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How to get the Android device's primary e-mail address
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As a friendly warning, be careful and up-front to the user when dealing with account, profile, and contact data. If you misuse a user's email address or other personal information, bad things can happen.
Method A: Use AccountManager (API level 5+)
You can use AccountManager.getAccounts or Accoun...
Get the current git hash in a Python script
I would like to include the current git hash in the output of a Python script (as a the version number of the code that generated that output).
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How to check Django version
...follow
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edited Aug 11 '19 at 8:33
user3956566
answered Jun 24 '11 at 13:30
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What is the difference between class and instance methods?
...ce methods use an instance of a class, whereas a class method can be used with just the class name. In Objective-C they are defined thusly:
@interface MyClass : NSObject
+ (void)aClassMethod;
- (void)anInstanceMethod;
@end
They could then be used like so:
[MyClass aClassMethod];
MyClass *obj...
What is a C++ delegate?
...{
// Normal class/struct members
int operator()(double d) // Arbitrary return types and parameter list
{
return (int) d + 1;
}
};
// Use:
Functor f;
int i = f(3.14);
Option 2: lambda expressions (C++11 only)
// Syntax is roughly: [capture](parameter list) -> r...
vs. . Which to use?
When looking at most sites (including SO), most of them use:
15 Answers
15
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Alternative timestamping services for Authenticode
...timestamp.verisign.com/scripts/timstamp.dll ") decides to go offline intermittently.
8 Answers
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Local and global temporary tables in SQL Server
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I find this explanation quite clear (it's pure copy from Technet):
There are two types of temporary tables: local and global. Local temporary tables are visible only to their creators during the same connection to an instance of SQL Server as when...