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Random row selection in Pandas dataframe
...me(x, n):
return x.ix[random.sample(x.index, n)]
Note: As of Pandas v0.20.0, ix has been deprecated in favour of loc for label based indexing.
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How can I increment a char?
...
180
In Python 2.x, just use the ord and chr functions:
>>> ord('c')
99
>>> ord('c...
Is there a “null coalescing” operator in JavaScript?
...Boolean(null)); // false
alert(Boolean(undefined)); // false
alert(Boolean(0)); // false
alert(Boolean("")); // false
alert(Boolean("false")); // true -- gotcha! :)
This means:
var whatIWant = null || new ShinyObject(); // is a new shiny object
var whatIWant = undefined || "well defined"; // is "...
Creating dataframe from a dictionary where entries have different lengths
Say I have a dictionary with 10 key-value pairs. Each entry holds a numpy array. However, the length of the array is not the same for all of them.
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Should one use < or
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The first is more idiomatic. In particular, it indicates (in a 0-based sense) the number of iterations. When using something 1-based (e.g. JDBC, IIRC) I might be tempted to use &lt;=. So:
for (int i=0; i &lt; count; i++) // For 0-based APIs
for (int i=1; i &lt;= count; i++) // For 1-ba...
Why do some C# lambda expressions compile to static methods?
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Action&lt;string&gt; withClosure = s =&gt; Console.WriteLine("My name is {0} and I am {1} years old", s, age);
Action&lt;string&gt; withoutClosure = s =&gt; Console.WriteLine("My name is {0}", s);
Console.WriteLine(withClosure.Method.IsStatic);
Console.WriteLine(withoutClosure.Method.IsStatic);
T...
Is short-circuiting logical operators mandated? And evaluation order?
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edited Sep 23 '11 at 15:07
answered Mar 10 '09 at 0:37
Al...
Types in MySQL: BigInt(20) vs Int(20)
...ous that they would allow for larger numbers; however, I can make an Int(20) or a BigInt(20) and that would make seem that it is not necessarily about size.
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How to convert comma-delimited string to list in Python?
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edited Apr 18 '13 at 0:36
answered Oct 21 '11 at 1:35
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Ruby: How to get the first character of a string
...h more readable. For instance, this:
class String
def initial
self[0,1]
end
end
will allow you to use the initial method on any string. So if you have the following variables:
last_name = "Smith"
first_name = "John"
Then you can get the initials very cleanly and readably:
puts first...