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How to get the last N rows of a pandas DataFrame?
... dataframe df1 and df2 (df1 is vanila dataframe, df2 is indexed by 'STK_ID' & 'RPT_Date') :
3 Answers
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Improve INSERT-per-second performance of SQLite
...more memory will be used for your database.
If you have indices, consider calling CREATE INDEX after doing all your inserts. This is significantly faster than creating the index and then doing your inserts.
You have to be quite careful if you have concurrent access to SQLite, as the whole database i...
How to increment a datetime by one day?
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All of the current answers are wrong in some cases as they do not consider that timezones change their offset relative to UTC. So in some cases adding 24h is different from adding a calendar day.
Proposed solution
The follo...
How can I store my users' passwords safely?
...tials';
}
(In case you are still using legacy 5.3.7 or newer you can install ircmaxell/password_compat to have access to the build-in functions)
Improving upon salted hashes: add pepper
If you want extra security, the security folks now (2017) recommend adding a 'pepper' to the (automatically)...
How to find all serial devices (ttyS, ttyUSB, ..) on Linux without opening them?
What is the proper way to get a list of all available serial ports/devices on a Linux system?
12 Answers
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What is a stored procedure?
... a couple of ways. Most major DBMs support stored procedures; however, not all do. You will need to verify with your particular DBMS help documentation for specifics. As I am most familiar with SQL Server I will use that as my samples.
To create a stored procedure the syntax is fairly simple:
CRE...
What is causing “Unable to allocate memory for pool” in PHP?
I've occasionally run up against a server's memory allocation limit, particularly with a bloated application like Wordpress, but never encountered "Unable to allocate memory for pool" and having trouble tracking down any information.
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How to determine if one array contains all elements of another array
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Perhaps this is easier to read:
a2.all? { |e| a1.include?(e) }
You can also use array intersection:
(a1 & a2).size == a1.size
Note that size is used here just for speed, you can also do (slower):
(a1 & a2) == a1
But I guess the first is more re...
Creating an empty Pandas DataFrame, then filling it?
...utocompletion), but that works with strings as date format, right? The overall approach works though (I changed index to something else).
– Matthias Kauer
Dec 15 '12 at 8:42
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WiX tricks and tips
...include file. Enables re-use, variables are faster to find and (if needed) allows for easier manipulation by an external tool.
Define Platform variables for x86 and x64 builds
<!-- Product name as you want it to appear in Add/Remove Programs-->
<?if $(var.Platform) = x64 ?>
<?defin...