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Why unsigned integer is not available in PostgreSQL?
...l.org/docs/9.4/static/sql-createdomain.html
CREATE DOMAIN name [ AS ] data_type
[ COLLATE collation ]
[ DEFAULT expression ]
[ constraint [ ... ] ]
where constraint is:
[ CONSTRAINT constraint_name ]
{ NOT NULL | NULL | CHECK (expression) }
Domain is like a type but with an addition...
Python Pandas merge only certain columns
...
Hmmm ... I tried using this to merge column 'Unique_External_Users' from df2 to df1 but got an error ... "None of [Index(['U', 'n', 'i', 'q', 'u', 'e', '', 'E', 'x', 't', 'e', 'r', 'n', 'a',\n 'l', '', 'U', 's', 'e', 'r', 's'],\n dtype='object')] are in the [column...
Determine Whether Two Date Ranges Overlap
...
Proof:
Let ConditionA Mean that DateRange A Completely After DateRange B
_ |---- DateRange A ------|
|---Date Range B -----| _
(True if StartA > EndB)
Let ConditionB Mean that DateRange A is Completely Before DateRange B
|---- DateRange A ...
What is the strict aliasing rule?
...sg) onto a buffer of the word size of your system (like a pointer to uint32_ts or uint16_ts). When you overlay a struct onto such a buffer, or a buffer onto such a struct through pointer casting you can easily violate strict aliasing rules.
So in this kind of setup, if I want to send a message to so...
Is “double hashing” a password less secure than just hashing it once?
...lled "key strengthening" or "key stretching". See en.wikipedia.org/wiki/Key_stretching
– user41871
Dec 7 '08 at 22:40
17
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How to write into a file in PHP?
...
You can use a higher-level function like:
file_put_contents($filename, $content);
which is identical to calling fopen(), fwrite(), and fclose() successively to write data to a file.
Docs: file_put_contents
...
How do you specify that a class property is an integer?
...// Helper for generating Opaque types.
type Opaque<T, K> = T & { __opaque__: K };
// 2 opaque types created with the helper
type Int = Opaque<number, 'Int'>;
type ID = Opaque<number, 'ID'>;
// using our types to differentiate our properties even at runtime
// they are still j...
Intro to GPU programming [closed]
...There are tons of cool materials to read.
http://www.nvidia.com/object/cuda_home.html
Hello world would be to do any kind of calculation using GPU.
Hope that helps.
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How to pip or easy_install tkinter on Windows
...nter these two commands:
>>> import tkinter
>>> tkinter._test()
This should pop up a small window; the first line at the top of the window should say "This is Tcl/Tk version 8.5"; make sure it is not 8.4!
2) Uninstall 64-bit Python and install 32 bit Python.
...
Python Regex - How to Get Positions and Values of Matches
...the span & group are indexed for multi capture groups in a regex
regex_with_3_groups=r"([a-z])([0-9]+)([A-Z])"
for match in re.finditer(regex_with_3_groups, string):
for idx in range(0, 4):
print(match.span(idx), match.group(idx))
...