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Create an empty data.frame
... File=character(),
User=character(),
stringsAsFactors=FALSE)
Here's an other example with different column types :
df <- data.frame(Doubles=double(),
Ints=integer(),
Factors=factor(),
Logicals=logical()...
Differences between ExpandoObject, DynamicObject and dynamic
...class MyNoCookiesInTheJarDynamicObject : DynamicObject
{
Dictionary<string, object> properties = new Dictionary<string, object>();
public override bool TryGetMember(GetMemberBinder binder, out object result)
{
if (properties.ContainsKey(binder.Name))
{
...
How do I get the difference between two Dates in JavaScript?
...ht do addition, coercion to number or concatenation. Since Dates coerce to String in this case, + does concatenation. Confusion is not the fault of the Date object, but of overloading operators.
– RobG
Mar 22 '16 at 23:53
...
What is for Python what 'explode' is for PHP?
I had a string which is stored in a variable myvar = "Rajasekar SP" . I want to split it with delimiter like we do using explode in PHP.
...
Change one value based on another value in pandas
...her columns by using the + operation which is overridden for series. Fancy string formatting, f-strings etc won't work here since the + applies to scalars and not 'primitive' values:
df['description'] = 'A ' + df.age.astype(str) + ' years old ' \
+ df.type + ' ' + df.animal
In ...
Unix command to find lines common in two files
...thing in 1.txt will be interpreted as a regular expression and not a plain string. Also, any blank line in 1.txt will match all lines in 2.txt. So grep will only work in very specific situations. You'd at least want to use fgrep (or grep -f) but the blank-line thing is probably going to wreak havoc ...
How to tell if a file is git tracked (by shell exit code)?
...in a script, for example PowerShell:
$gitResult = (git ls-files $_) | out-string
if ($gitResult.length -ne 0)
{
## do stuff with the tracked file
}
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Is it better to use Enumerable.Empty() as opposed to new List() to initialize an IEnumerable
...ing it to a new list in the constructor:
public class Person
{
public string Name { get; set; }
public IList<Role> Roles { get; private set; }
public Person()
{
Roles = new List<Role>();
}
}
If you really really want to have the public setter, leave Roles ...
When to use DataContract and DataMember attributes?
...to and from XML). All .NET Framework primitive types, such as integers and strings, as well as certain types treated as primitives, such as DateTime and XmlElement, can be serialized with no other preparation and are considered as having default data contracts. Many .NET Framework types also have ex...
Creating and throwing new exception
...und."
}
To throw a general exception use the throw command followed by a string.
throw "Error trying to do a task"
When used inside a catch, you can provide additional information about what triggered the error
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