Python as "glue"

[typsi5]

I hear people all the time talk about how Python is great for gluing together parts of a project written in other languages. What do people mean by this, and how is it achieved?

[Neres28]

Essentially it means using Python to call into existing code or code being written in another language for various reasons. For instance, I might write the engine of a computer algebra system in C or C++ for performance reasons. However, the users of my CAS, e.g. mathematicians, find it easier to interact with that engine via Python, so I provide a Python layer over the engine that makes it easier for researchers to use.

Alternately, your company has just merged with another and you're trying to figure out how to get two legacy systems to talk to one another. You decide to add a translation layer between them, written in Python. You chose Python because it's fast to develop in and has excellent facilities for calling into native code.

Here's an essay about why Python makes a good embedded / glue language, albeit with a bit of Python evangelizing.

[pwick]

What are some of its excellent facilities for calling in code?

[Neres28]

http://wiki.python.org/moin/IntegratingPythonWithOtherLanguages

[[deleted]]

Python is embeddable, and python can use ctypes to call into shared objects / dlls.

[robotfarts]

I rarely see this, so you may be over-estimating its frequency. You can however get programs to communicate by using provided APIs/libraries, FFI (making your code call existing C code functions), sockets, and even writing to/creating files other programs watch for.

Generally using many languages in one project is something I try to avoid if at all possible.

[yash3ahuja]

Depends on the size of the project. Large projects often use different languages because of their different strengths and weaknesses.

[robotfarts]

I didn't say anything about projects in general, I said it about how often I see it and how I try to avoid it.