Container package for libusb

This Python package functions as an installation vehicle for libusb shared libraries, to simplify installation of tools that require libusb. The main use case is so that users don't have to install libusb manually for projects that use pyusb. However, any Python project that uses a libusb wrapper can also benefit.

APIs

There are three public functions exported by libusb_package.

• find(*args, **kwargs): Wrapper around pyusb's usb.core.find() that sets the backend parameter to a libusb1 backend created from the libusb library included in libusb_package. All other parameters are passed unmodified

• get_libusb1_backend(): Returns a pyusb backend object for the libusb version contained in libusb_package.

• find_library(candidate): Lower level function that returns either the full path to a library contained in libusb_package with a name starting with candidate, or None if no matching library is found. This function is suitable for use with the find_library callback parameter for pyusb's get_backend() functions.

Both get_libusb1_backend() and find_library(candidate) cache their return values.

Examples

Usage example for find():

import libusb_package

for dev in libusb_package.find(find_all=True):
    print(dev)

Usage example for find_library():

import libusb_package
import usb.core
import usb.backend.libusb1

libusb1_backend = usb.backend.libusb1.get_backend(find_library=libusb_package.find_library)
# -> calls usb.libloader.load_locate_library(
#                ('usb-1.0', 'libusb-1.0', 'usb'),
#                'cygusb-1.0.dll', 'Libusb 1',
#                win_cls=win_cls,
#                find_library=find_library, check_symbols=('libusb_init',))
#
# -> calls find_library(candidate) with candidate in ('usb-1.0', 'libusb-1.0', 'usb')
#   returns lib name or path (as appropriate for OS) if matching lib is found

# It would also be possible to pass the output of libusb_package.get_libsusb1_backend()
# to the backend parameter here. In fact, that function is simply a shorthand for the line
# above.
print(list(usb.core.find(find_all=True, backend=libusb1_backend)))