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How do I create an empty array/matrix in NumPy?
I can't figure out how to use an array or matrix in the way that I would normally use a list. I want to create an empty array (or matrix) and then add one column (or row) to it at a time.
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How can I convert ereg expressions to preg in PHP?
Since POSIX regular expressions (ereg) are deprecated since PHP 5.3.0, I'd like to know an easy way to convert the old expressions to PCRE (Perl Compatible Regular Expressions) (preg) .
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Are 2^n and n*2^n in the same time complexity?
...found on time complexity are unclear about when it is okay to ignore terms in a time complexity equation, specifically with non-polynomial examples.
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How to clear basic authentication details in chrome
I'm working on a site that uses basic authentication. Using Chrome I've logged in using the basic auth. I now want to remove the basic authentication details from the browser and try a different login.
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How to manage local vs production settings in Django?
What is the recommended way of handling settings for local development and the production server? Some of them (like constants, etc) can be changed/accessed in both, but some of them (like paths to static files) need to remain different, and hence should not be overwritten every time the new code is...
How do I test a file upload in rails?
I have a controller which is responsible for accepting JSON files and then processing the JSON files to do some user maintenance for our application. In user testing the file upload and processing works, but of course I would like to automate the process of testing the user maintenance in our testin...
Are Exceptions in C++ really slow
I was watching Systematic Error Handling in C++—Andrei Alexandrescu he claims that Exceptions in C++ are very very slow.
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Finding the source code for built-in Python functions?
Is there a way to see how built in functions work in python? I don't mean just how to use them, but also how were they built, what is the code behind sorted or enumerate etc...?
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Pandas - How to flatten a hierarchical index in columns
I have a data frame with a hierarchical index in axis 1 (columns) (from a groupby.agg operation):
17 Answers
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Why .NET String is immutable? [duplicate]
As we all know, String is immutable. What are the reasons for String being immutable and the introduction of StringBuilder class as mutable?
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