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Apply multiple functions to multiple groupby columns

... dictionary of dictionaries to the agg groupby method. Second, never use .ix. If you desire to work with two separate columns at the same time I would suggest using the apply method which implicitly passes a DataFrame to the applied function. Let's use a similar dataframe as the one from above df ...
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Check if multiple strings exist in another string

How can I check if any of the strings in an array exists in another string? 15 Answers ...
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What optimizations can GHC be expected to perform reliably?

... This GHC Trac page also explains the passes fairly well. This page explains the optimization ordering, though, like the majority of the Trac Wiki, it is out of date. For specifics, the best thing to do is probably to look at how a specific program i...
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Is there a standardized method to swap two variables in Python?

In Python, I've seen two variable values swapped using this syntax: 7 Answers 7 ...
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Using Python String Formatting with Lists

... varying number of %s tokens, which match the number of entries in list x . I need to write out a formatted string. The following doesn't work, but indicates what I'm trying to do. In this example, there are three %s tokens and the list has three entries. ...
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What is the difference between a generative and a discriminative algorithm?

... Let's say you have input data x and you want to classify the data into labels y. A generative model learns the joint probability distribution p(x,y) and a discriminative model learns the conditional probability distribution p(y|x) - which you should read ...
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What is the most accurate way to retrieve a user's correct IP address in PHP?

...ess: function get_ip_address(){ foreach (array('HTTP_CLIENT_IP', 'HTTP_X_FORWARDED_FOR', 'HTTP_X_FORWARDED', 'HTTP_X_CLUSTER_CLIENT_IP', 'HTTP_FORWARDED_FOR', 'HTTP_FORWARDED', 'REMOTE_ADDR') as $key){ if (array_key_exists($key, $_SERVER) === true){ foreach (explode(',', $_SE...
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What would cause an algorithm to have O(log n) complexity?

...r of steps will be logarithmic. So where does this come up? One classic example is binary search, a fast algorithm for searching a sorted array for a value. The algorithm works like this: If the array is empty, return that the element isn't present in the array. Otherwise: Look at the middle ...
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How to convert a Binary String to a base 10 integer in Java

... You need to specify the radix. There's an overload of Integer#parseInt() which allows you to. int foo = Integer.parseInt("1001", 2); share | improve ...
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Migrating from JSF 1.2 to JSF 2.0

...echnology which you are currently using and which you want to use. JSP 2.x to JSP 2.x = Almost no effort. Facelets 1.x to Facelets 2.0 = Little effort. JSP 2.x to Facelets 2.0 = Lot of effort. Double this if you also have custom components. Basic changes Regardless of the view technology swit...