How do I find out what Python libraries are installed on my Mac?

Question

I'm just starting out with Python, and have found out that I can import various libraries. How do I find out what libraries exist on my Mac that I can import? How do I find out what functions they include?

I seem to remember using some web server type thing to browse through local help files, but I may have imagined that!

Answer 1

From the Python REPL (the command-line interpreter / Read-Eval-Print-Loop), type help("modules") to see a list of all your available libs.

Then to see functions within a module, do help("posix"), for example. If you haven't imported the library yet, you have to put quotes around the library's name.

Answer 2

Every standard python distribution has these libraries, which cover most of what you will need in a project.

In case you need to find out if a library exists at runtime, you do it like this

try:
    import ObscureModule
except ImportError:
    print "you need to install ObscureModule"
    sys.exit(1) # or something like that

Answer 3

On Leopard, depending on the python package you're using and the version number, the modules can be found in /Library/Python:

/Library/Python/2.5/site-packages

or in /Library/Frameworks

/Library/Frameworks/Python.framework/Versions/Current/lib/python2.6/site-packages

(it could also be 3.0 or whatever version)... I guess it is quite the same with Tiger

Answer 4

You can install another library: yolk.

yolk is a python package manager and will show you everything you have added via pypi. But it will also show you site-packages added through whatever local package manager you run.

Answer 5

just run the Python interpeter and type the command import "lib_name" if it gives an error, you don't have the lib installed...else you are good to go

Answer 6

For the web server, you can run the pydoc module that is included in the python distribution as a script:

python /path/to/pydoc.py -p 1234

where 1234 is the port you want the server to run at. You can then visit http://localhost:1234/ and browse the documentation.