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Replace None with NaN in pandas dataframe
...ata from an SQL database, you can combine this with the answer below. This converts None (which isn't a string) to NaN. Then you can df['column'].replace(nan, "", inplace=True) if say you wanted None to be empty string.
– VISQL
Jul 4 '18 at 12:52
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How to find gaps in sequential numbering in mysql?
... far faster than the accepted answer. The only thing that I'd add is that CONVERT( YourCol, UNSIGNED ) will give better results if YourCol isn't already an integer.
– Barton Chittenden
Feb 10 '17 at 23:36
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How to build a query string for a URL in C#?
... When I've done similar things I've usually been interested in serialising AND deserialising so my suggestion is to build a NameValueCollection up and then pass to:
using System.Linq;
using System.Web;
using System.Collections.Specialized;
private string ToQueryString(NameValueCollection nvc)
{
...
How to get the list of all printers in computer
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Get Network and Local Printer List in ASP.NET
This method uses the Windows Management Instrumentation or the WMI interface. It’s a technology used to get information about various systems (hardware) running on a Windows Operating Syst...
C# Pass Lambda Expression as Method Parameter
I have a lambda expression that I'd like to be able to pass around and reuse. Here's the code:
4 Answers
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Avoiding SQL injection without parameters
...weird. The parser is capable of identifying constants in the text and can convert the SQL string to one the uses parameters artificially. It can then insert into the cache the text of this new parameterised query. Subsequent similar SQL may find its parameterised version matched in the cache. Ho...
Does JSON syntax allow duplicate keys in an object?
...<a>x</a>
<a>y</a>
</object>
When this is converted into JSON, you get the following:
{
"object": {
"a": [
"x",
"y"
]
}
}
A natural mapping from a language that handles what you might call duplicate keys to another, can serve as a potential...
Using Excel OleDb to get sheet names IN SHEET ORDER
... That's code I'd like to see! How can you query for 'the Nth sheet' and the number of sheets?
– Steve Cooper
Jul 23 '09 at 8:27
13
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Run an untrusted C program in a sandbox in Linux that prevents it from opening files, forking, etc.?
...was wondering if there exists a way to run an untrusted C program under a sandbox in Linux. Something that would prevent the program from opening files, or network connections, or forking, exec, etc?
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How to make a Python script run like a service or daemon in Linux
I have written a Python script that checks a certain e-mail address and passes new e-mails to an external program. How can I get this script to execute 24/7, such as turning it into daemon or service in Linux. Would I also need a loop that never ends in the program, or can it be done by just havin...