Generating c source for a binary edition
This is extremely convenient. Clearly, if you are building code from scratch and need speed, Cython is an excellent option. For this I really must congratulate the Cython and Pyrex developers.
It took me 10 minutes to figure it out how Cython works and I gained a speed up of times!!! Successful in the sense that it was much faster than all code written by my predecessors mainly because the speed scales almost linearly with the number of cores. Also, the code is shorter and much easier to read and maintain.
As a Perl lover, this was impressive. We still get all the benefits of Python such as rapid development and clean object-oriented design patterns but with the speed of C. By simply replacing the class that contained the differential equation with a Cython version the calculation time dropped by a factor 5.
Not bad for half a Sunday afternoons work. I did not have to mess with make files or configure the compiles. Cython integrated well with NumPy and SciPy. This expands the programming tasks you can do with Python substantially. Their user base has tons of legacy code or external libraries that they need to interface, and most of the reason Python has had such a great adoption curve in that space is because Numpy has made the data portion of that interface easy.
Cython makes the code portion quite painless, as well. Just doing that, with no Cython specific code reduced the time of processing 10K records from 2. Not bad for that little work. This way on machines that do not have a compiler users can still use fastavro. The end result is a package that reads Avro faster than Java and supports both Python 2 and Python 3. Using Cython and a little bit of work th[is] was achieved without too much effort.
Zaytsev and Abigail Morrison. Both the Cython version and the C version are about 70x faster than the pure Python version, which uses Numpy arrays.
Fantastic way to write Python bindings for native libs or speed up computationally intensive code without having to write C yourself. It's been a huge boon. Having used swig, hand writing wrappers, and pyrex before i can say i much prefer cython.
Thank you for the hard work. Using cython it went from running single calculation in hours to seconds, focking nice The worst you'll usually get is a lack of performance gain at which point cython -a is your friend. Wringing out all the performance you can get can require a reasonable working knowledge of C -- but you don't have to know it that well to do pretty darn well.
It's unfortunate that it's not as wide-spread and I think it's kind-a underappreciated what you can do in Cython. Essentially, it's a superset of the Python language, you can strictly type it and it will compile to C and you will have C speed.
You can easily achieve it, with a syntax more similar to Python. Definitely check out Cython. About Cython Cython is an optimising static compiler for both the Python programming language and the extended Cython programming language based on Pyrex. Cython Tutorial ; Fast Numerical Computations with Cython If you still have questions, feel free to send an email to the cython users mailing list.
Download Cython is freely available under the open source Apache License. In this case, we use include in order to be able to use functions such as printf and scanf , whose declarations are located in the file stdio. C compilers do not allow you to use a function unless it has previously been declared or defined in that file; include statements are thus the way to re-use previously-written code in your C programs.
There are a number of other preprocessor commands as well, but we will deal with them as we need them. After the C preprocessor has included all the header files and expanded out all the define and include statements as well as any other preprocessor commands that may be in the original file , the compiler can compile the program.
It does this by turning the C source code into an object code file, which is a file ending in ". Object code is not directly executable, though. In order to make an executable, you also have to add code for all of the library functions that were include d into the file this is not the same as including the declarations, which is what include does. This is the job of the linker see the next section. This tells the compiler to run the preprocessor on the file foo.
The -c option means to compile the source code file into an object file but not to invoke the linker. If your entire program is in one source code file, you can instead do this:. This tells the compiler to run the preprocessor on foo.
The -o option states that the next word on the line is the name of the binary executable file program. If you don't specify the -o , i. Note also that the name of the compiler we are using is gcc , which stands for "GNU C compiler" or "GNU compiler collection" depending on who you listen to. Other C compilers exist; many of them have the name cc , for "C compiler".
On Linux systems cc is an alias for gcc. The job of the linker is to link together a bunch of object files. This includes both the object files that the compiler created from your source code files as well as object files that have been pre-compiled for you and collected into library files. These files have names which end in.
Like the preprocessor, the linker is a separate program called ld. Also like the preprocessor, the linker is invoked automatically for you when you use the compiler. The normal way of using the linker is as follows:. This line tells the compiler to link together three object files foo. This is all you need to know to begin compiling your own C programs. Generally, we also recommend that you use the -Wall command-line option:. The -Wall option causes the compiler to warn you about legal but dubious code constructs, and will help you catch a lot of bugs very early.
If you want to be even more anal and who doesn't? The -Wstrict-prototypes option means that the compiler will warn you if you haven't written correct prototypes for all your functions.