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Naming returned columns in Pandas aggregate function? [duplicate]
...er, this does not work with lambda functions, since they are anonymous and all return <lambda>, which causes a name collision:
>>> df.groupby('A').agg({'B': [lambda x: x.min(), lambda x: x.max]})
SpecificationError: Function names must be unique, found multiple named <lambda>
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Reverse a string in Python
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@Tanner [::-1] is fastest because it does not call any external functions, rather it's using slicing, which is highly-optimized in python. ''.join(list(reversed(s))) makes 3 function calls.
– hd1
Apr 27 at 13:51
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How to create a DataTable in C# and how to add rows?
...ma/structure, do:
dt.WriteXMLSchema("dtSchemaOrStructure.xml");
Additionally, you can also export your data:
dt.WriteXML("dtDataxml");
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How can we generate getters and setters in Visual Studio?
...the property directly below the private field, which bugs me, because I usually have all of my private fields grouped together, and this Visual Studio feature breaks my class' formatting.
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Changing the image source using jQuery
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Yes. This finally did the trick. .destroy() doesn't go nearly far enough. Nuking all the html and than init again actually works when swapping out images of various sizes and such.
– Matt J.
Apr 11 '...
Autoreload of modules in IPython [duplicate]
Is there a way to have IPython automatically reload all changed code? Either before each line is executed in the shell or failing that when it is specifically requested to. I'm doing a lot of exploratory programming using IPython and SciPy and it's quite a pain to have to manually reload each module...
Scala: What is a TypeTag and how do I use it?
All I know about TypeTags is that they somehow replaced Manifests. Information on the Internet is scarce and doesn't provide me with a good sense of the subject.
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Find MongoDB records where array field is not empty
All of my records have a field called "pictures". This field is an array of strings.
11 Answers
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Is there an IDictionary implementation that, on missing key, returns the default value instead of th
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Indeed, that won't be efficient at all.
You could always write an extension method:
public static TValue GetValueOrDefault<TKey,TValue>
(this IDictionary<TKey, TValue> dictionary, TKey key)
{
TValue ret;
// Ignore return value
dic...
Tips for debugging .htaccess rewrite rules
...as many respondents suggest. Also there are many .htaccess -specific pitfalls and constraints are aren't covered well. Setting up a local test LAMP stack involves too much of a learning curve for most.
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