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Convert a list of data frames into one data frame
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Use bind_rows() from the dplyr package:
bind_rows(list_of_dataframes, .id = "column_label")
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PHP - Debugging Curl
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You can enable the CURLOPT_VERBOSE option:
curl_setopt($curlhandle, CURLOPT_VERBOSE, true);
When CURLOPT_VERBOSE is set, output is written to STDERR or the file specified using CURLOPT_STDERR. The output is very informative.
You can also use tcpdu...
What is the reason for having '//' in Python? [duplicate]
...ement Alex's response, I would add that starting from Python 2.2.0a2, from __future__ import division is a convenient alternative to using lots of float(…)/…. All divisions perform float divisions, except those with //. This works with all versions from 2.2.0a2 on.
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Creating an empty bitmap and drawing though canvas in Android
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This is probably simpler than you're thinking:
int w = WIDTH_PX, h = HEIGHT_PX;
Bitmap.Config conf = Bitmap.Config.ARGB_8888; // see other conf types
Bitmap bmp = Bitmap.createBitmap(w, h, conf); // this creates a MUTABLE bitmap
Canvas canvas = new Canvas(bmp);
// ready to draw on t...
Setting element of array from Twig
..., for example :
{% for key , value in t%}
{% set temp= temp|merge({(key~'_'):value}) %}
{% endfor %}
t keys : 0 , 1 , 2 ..
temp keys : 0_, 1_ , 2_ ....
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SQL Server Regular expressions in T-SQL
...oks Online)
Wildcard Meaning
% Any string of zero or more characters.
_ Any single character.
[ ] Any single character within the specified range
(for example, [a-f]) or set (for example, [abcdef]).
[^] Any single character not within the specified range
(for example, [^a - f]) or s...
Java 7 language features with Android
...tch
Multiple-catch (catch (Exc1 | Exc2 e))
Underscore in number literals (1_234_567)
Binary literals (0b1110111)
And these features cannot be used yet:
The try-with-resources statement — because it requires the non-existing interface "java.lang.AutoCloseable" (this can be used publicly in 4.4+...
How to select rows from a DataFrame based on column values?
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To select rows whose column value equals a scalar, some_value, use ==:
df.loc[df['column_name'] == some_value]
To select rows whose column value is in an iterable, some_values, use isin:
df.loc[df['column_name'].isin(some_values)]
Combine multiple conditions with &:
d...
How to delete an object by id with entity framework
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I am using the following code in one of my projects:
using (var _context = new DBContext(new DbContextOptions<DBContext>()))
{
try
{
_context.MyItems.Remove(new MyItem() { MyItemId = id });
await _context.SaveChangesAsync();
}
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MongoDB Many-to-Many Association
...intain the roles in separate documents then you can include the document's _id in the roles array instead of the name:
{name:"Joe"
,roles:["4b5783300334000000000aa9","5783300334000000000aa943","6c6793300334001000000006"]
}
and set up the roles like:
{_id:"6c6793300334001000000006"
,rolename:"Eng...