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Change column type from string to float in Pandas
...
You have four main options for converting types in pandas:
to_numeric() - provides functionality to safely convert non-numeric types (e.g. strings) to a suitable numeric type. (See also to_datetime() and to_timedelta().)
astype() - convert (almost) any type to (almost) any other type ...
Difference between DirectCast() and CType() in VB.NET
... convert a string to an integer. It has as much power as calling Convert.To___() in C#, where the ___ is the target type of your cast.
This is desirable because it's very powerful. However, this power comes at the cost of performance; it's not as fast as DirectCast() or C#'s cast operator because i...
How to merge YAML arrays?
...y be able to achieve this as follows:
# note: no dash before commands
some_stuff: &some_stuff |-
a
b
c
combined_stuff:
- *some_stuff
- d
- e
- f
This is equivalent to:
some_stuff: "a\nb\nc"
combined_stuff:
- "a\nb\nc"
- d
- e
- f
I have been using this on my g...
Create a CSV File for a user in PHP
...!== false || strpos($string, "\n") !== false) {
$string = '"' . str_replace('"', '""', $string) . '"';
}
return $string;
}
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Truncating floats in Python
...imal module
str(Decimal(s).quantize(Decimal((0, (1,), -n)), rounding=ROUND_DOWN))
The first step, converting to a string, is quite difficult because there are some pairs of floating point literals (i.e. what you write in the source code) which both produce the same binary representation and yet s...
How can I find the version of the Fedora I use?
...something like:
$ source /etc/os-release
$ echo $ID
fedora
$ echo $VERSION_ID
17
$ echo $VERSION
17 (Beefy Miracle)
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SQL Server Installation - What is the Installation Media Folder?
...se that one when you "Browse for SQL server Installation Media"
SQLEXPRADV_x64_ENU.exe > SQLEXPRADV_x64_ENU.zip
7zip will open it (standard Windows zip doesn't work though)
Extract to something like C:\SQLInstallMedia
You will get folders like 1033_enu_lp, resources, x64 and a bunch of files....
What is the fastest way to compute sin and cos together?
...OR A PARTICULAR PURPOSE.
$ cat main.c
#include <math.h>
struct Sin_cos {double sin; double cos;};
struct Sin_cos fsincos(double val) {
struct Sin_cos r;
r.sin = sin(val);
r.cos = cos(val);
return r;
}
$ gcc -c -S -O3 -ffast-math -mfpmath=387 main.c -o main.s
$ cat main.s
.tex...
What is an ORM, how does it work, and how should I use one? [closed]
...ch the author is "Linus". Manually, you would do something like that:
book_list = new List();
sql = "SELECT book FROM library WHERE author = 'Linus'";
data = query(sql); // I over simplify ...
while (row = data.next())
{
book = new Book();
book.setAuthor(row.get('author');
book_list....
find vs find_by vs where
...d are usually replaced with things like this:
Model.all
Model.first
find_by is used as a helper when you're searching for information within a column, and it maps to such with naming conventions. For instance, if you have a column named name in your database, you'd use the following syntax:
Mod...