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How to test if list element exists?
...to check that the name is actually defined in the list:
foo <- list(a=42, b=NULL)
foo
is.null(foo[["a"]]) # FALSE
is.null(foo[["b"]]) # TRUE, but the element "exists"...
is.null(foo[["c"]]) # TRUE
"a" %in% names(foo) # TRUE
"b" %in% names(foo) # TRUE
"c" %in% names(foo) # FALSE
...and foo[["...
Using an RDBMS as event sourcing storage
...oned state-based persistence). Therefore I wouldn't recommend option 1 and 2 at all.
Below is the schema as used in Ncqrs. As you can see, the table "Events" stores the related data as a CLOB (i.e. JSON or XML). This corresponds to your option 3 (Only that there is no "ProductEvents" table because ...
CSS two divs next to each other
...ut two <div> s next to each other. The right <div> is about 200px; and the left <div> must fill up the rest of the screen width? How can I do this?
...
Multiple inheritance/prototypes in JavaScript
...et is a function or a constructor.
Example
// Creating objects
var o1, o2, o3,
obj = multiInherit(o1={a:1}, o2={b:2}, o3={a:3, b:3});
// Checking property existences
'a' in obj; // true (inherited from o1)
'b' in obj; // true (inherited from o2)
'c' in obj; // false (not found)
// Sett...
How to reset db in Django? I get a command 'reset' not found error
...
answered Mar 16 '13 at 20:00
robertkleprobertklep
164k2727 gold badges308308 silver badges300300 bronze badges
...
SonarQube Exclude a directory
...
124
Try something like this:
sonar.exclusions=src/java/test/**
...
Add a background image to shape in XML Android
...
225
Use following layerlist:
<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:an...
How to add a WiX custom action that happens only on uninstall (via MSI)?
...|
edited Nov 19 '19 at 7:52
nelsonjchen
20855 silver badges1313 bronze badges
answered Apr 8 '09 at 20:3...
Converting a Pandas GroupBy output from Series to DataFrame
...ndex, though:
In [19]: type(g1)
Out[19]: pandas.core.frame.DataFrame
In [20]: g1.index
Out[20]:
MultiIndex([('Alice', 'Seattle'), ('Bob', 'Seattle'), ('Mallory', 'Portland'),
('Mallory', 'Seattle')], dtype=object)
Perhaps you want something like this?
In [21]: g1.add_suffix('_Count').re...
How to disable text selection using jQuery?
...
274
In jQuery 1.8, this can be done as follows:
(function($){
$.fn.disableSelection = functio...