pandas has a replace method too: In [25]: df = DataFrame({1: [2,3,4], 2: [3,4,5]}) In [26]: df Out[26]: 1 2 0 2 3 1 3 4 2 4 5 In [27]: df[2] Out[27]: 0 3 1 4 2 5 Name: 2 In [28]: df[2].replace(4, 17) Out[28]: 0 3 1 17 2 5 Name: 2 In … Read more
Here’s a simple example implementation: #include <string> #include <vector> #include <sstream> #include <utility> std::vector<std::string> explode(std::string const & s, char delim) { std::vector<std::string> result; std::istringstream iss(s); for (std::string token; std::getline(iss, token, delim); ) { result.push_back(std::move(token)); } return result; } Usage: auto v = explode(“hello world foo bar”, ‘ ‘); Note: @Jerry’s idea of writing to an … Read more
Yes, it is virtualenv along with virtualenvwrapper. update: you may install both at once with virtualenv burrito. Update: the correct answer is now probably pyenv. For scientific computing, the corresponding tool is anaconda.
This is a classic mistake. i in your case is already an element from array (i.e. another list), not an index of array (not an int), so if Volume == i[2]: counter += 1 You can check the Python tutorial. Also, try doing this: for i in array: print (i) And see what you get! … Read more
You can have static blocks in C++ as well – outside classes. It turns out we can implement a Java-style static block, albeit outside of a class rather than inside it, i.e. at translation unit scope. The implementation is a bit ugly under the hood, but when used it’s quite elegant! Downloadable version There’s now … Read more
There’s __debug__, which is a special value that the compiler does preprocess. if __debug__: print “If this prints, you’re not running python -O.” else: print “If this prints, you are running python -O!” __debug__ will be replaced with a constant 0 or 1 by the compiler, and the optimizer will remove any if 0: lines … Read more
Sadly – no. The closest you can do is: int y = (x != null) ? x : -1; Of course, you can wrap this up in library methods if you feel the need to (it’s unlikely to cut down on length much), but at the syntax level there isn’t anything more succinct available.
You could use Enumerable.Repeat: byte[] a = Enumerable.Repeat((byte)10, 100).ToArray(); The first parameter is the element you want repeated, and the second parameter is the number of times to repeat it. This is OK for small arrays but you should use the looping method if you are dealing with very large arrays and performance is a … Read more
Just recently I also needed an arbitrary precision decimal in C# and came across the idea posted here: https://stackoverflow.com/a/4524254/804614 I then completed the draft to support all basic arithmetic and comparison operators, as well as conversions to and from all typical numerical types and a few exponential methods, which I needed at that time. It … Read more
XSLT equivalents for JSON – a list of candidates (tools and specs) Tools 1. XSLT You can use XSLT for JSON with the aim of fn:json-to-xml. This section describes facilities allowing JSON data to be processed using XSLT. 2. jq jq is like sed for JSON data – you can use it to slice and … Read more