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Importing Quills can be tricky.  It is a compiled module, it is not necessarily installed in a location that macOS searches by default, and it supports a variety of architectures and Python versions.


As described in Architecture, MacTerm has two major goals that complicate imports: it wants to avoid requiring an installer with administrator privileges, and it wants to support several versions of macOS and Python.

So, in the MacTerm front-end, the runtime linker and Python interpreter are manually instructed on how to find components, and each component has a different location depending on the version of the OS.

Example of Importing Quills

In the MacTerm application bundle, you will find two scripts that demonstrate how importing is achieved in a highly portable way:

The Architecture page contains full details on the directory structure of components.

Prerequisites for Importing

If you write your own scripts that rely on Quills, you must perform the same steps to locate libraries as those in the example scripts above (assuming you still want to support all macOS versions; see below).

Quills is partly compiled, as noted in Architecture, so you must make sure both the compiled and Python parts are found.  There are two key locations:

To set the library path, define the DYLD_LIBRARY_PATH environment variable (or an equivalent) before starting your Python interpreter (i.e. use the parent shell).  Run man dyld for more information on linker search paths.

Sometimes, installing a framework in a path that macOS searches by default, such as /Library/Frameworks, allows you to avoid setting a library path at all.  However, MacTerm has not yet been tested with this configuration, and attempting to install the Quills framework system-wide is discouraged.

The module path can be set in a few ways:

As noted in Architecture, the version of macOS that is in use may dictate both the path to the compiled component and the path to the script bindings (Python module).  If your personal script does not care about older versions of macOS, you can take a simpler approach and only deal with the paths that matter for your computer.

Writing Quills-Dependent Python Scripts

Assuming you have used the steps above to set up an appropriate environment to find frameworks, the following approach is recommended for actually importing modules in your Python code:

        from quills import Base, Events, Prefs, Session, Terminal
    except ImportError, err:
        import sys
        print >>sys.stderr, "Unable to import Quills."
        if "DYLD_LIBRARY_PATH" in os.environ:
            print >>sys.stderr, "Shared library path:", os.environ["DYLD_LIBRARY_PATH"]
        print >>sys.stderr, "Python path:", sys.path
        raise err

The advantage of the above code is that failed imports will show you where the linker and the interpreter are actually looking for frameworks and Python modules; the default message is less helpful.