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python pandas dataframe to dictionary
I've a two columns dataframe, and intend to convert it to python dictionary - the first column will be the key and the second will be the value. Thank you in advance.
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MYSQL OR vs IN performance
... not believe people who give their "opinion", science is all about testing and evidence.
I ran a loop of 1000x the equivalent queries (for consistency, I used sql_no_cache):
IN: 2.34969592094s
OR: 5.83781504631s
Update:
(I don't have the source code for the original test, as it was 6 years ago, ...
input() error - NameError: name '…' is not defined
...es whatever your enter, as a Python expression. If you simply want to read strings, then use raw_input function in Python 2.7, which will not evaluate the read strings.
If you are using Python 3.x, raw_input has been renamed to input. Quoting the Python 3.0 release notes,
raw_input() was rename...
How do I query for all dates greater than a certain date in SQL Server?
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Try enclosing your date into a character string.
select *
from dbo.March2010 A
where A.Date >= '2010-04-01';
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What is the meaning of the 'g' flag in regular expressions?
... the regular expression should be tested against all possible matches in a string.
Without the g flag, it'll only test for the first.
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Oracle SQL: Update a table with data from another table
...ere is no matching row in t2. Without it, every row in t1 will be updated and the values will be set to NULL if there is no matching row in t2. That is generally not what you want to happen so the WHERE EXISTS is generally needed.
– Justin Cave
Aug 5 '13 at 1...
What is a callback?
...a semantic Func or Action.
public delegate void WorkCompletedCallBack(string result);
public void DoWork(WorkCompletedCallBack callback)
{
callback("Hello world");
}
public void Test()
{
WorkCompletedCallBack callback = TestCallBack; // Notice that I am ref...
How do I merge two dictionaries in a single expression in Python (taking union of dictionaries)?
...frozensets or tuples), but this method fails in Python 3 when keys are not strings.
>>> c = dict(a, **b)
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
TypeError: keyword arguments must be strings
From the mailing list, Guido van Rossum, the creator of...
How do I get the last inserted ID of a MySQL table in PHP?
...se, don't use mysql_* functions in new code. They are no longer maintained and are officially deprecated. See the red box? Learn about prepared statements instead, and use PDO or MySQLi - this article will help you decide which. If you choose PDO, here is a good tutorial.
But if you have to, use m...
How to auto-generate a C# class file from a JSON string [closed]
Given the following JSON object,
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