OxidizedFinder Meta Path Finder¶
OxidizedFinder is a Python type implementing a custom and
fully-featured meta path finder.
Oxidized is in its name because it is implemented in Rust.
Unlike traditional meta path finders which have to dynamically
discover resources (often by scanning the filesystem),
OxidizedFinder instances maintain an index of known
resources. When a resource is requested,
can retrieve that resource by effectively performing 1 or 2 lookups
in a Rust
HashMap. This makes resource resolution extremely efficient,
as no filesystem probing or other explicit I/O is performed.
OxidizedFinder are optionally bound to binary
blobs holding packed resources data. This is a custom serialization format
for expressing Python modules (source and bytecode), Python extension
modules, resource files, shared libraries, etc. This data format
along with a Rust library for interacting with it are defined by the
OxidizedFinder instance is created, the packed resources
data is parsed into a Rust data structure. On a modern machine, parsing
this resources data for the entirety of the Python standard library
takes ~1 ms.
OxidizedFinder instances can index built-in extension modules
and frozen modules, which are compiled into the Python interpreter. This
OxidizedFinder to subsume functionality normally provided by
FrozenImporter meta path finders,
allowing you to potentially replace
sys.meta_path with a single
OxidizedFinder in PyOxidizer Applications¶
When running from an application built with PyOxidizer (or using the
pyembed crate directly), an
OxidizedFinder instance will
(likely) be automatically registered as the first element in
sys.meta_path when starting a Python interpreter.
You can verify this inside a binary built with PyOxidizer:
>>> import sys >>> sys.meta_path [<OxidizedFinder object at 0x7f16bb6f93d0>]
Contrast with a typical Python environment:
>>> import sys >>> sys.meta_path [ <class '_frozen_importlib.BuiltinImporter'>, <class '_frozen_importlib.FrozenImporter'>, <class '_frozen_importlib_external.PathFinder'> ]
OxidizedFinder instance will (likely) be associated with
resources data embedded in the binary.
OxidizedFinder instance is constructed very early during Python
interpreter initialization. It is registered on
import requesting a
.pyc is performed, allowing
it to service every
import except those from the very few built-in
extension modules that are compiled into the interpreter and loaded as
part of Python initialization (e.g. the
OxidizedFinder is being installed on
path_hook method will be registered
as the first item on
If filesystem importing is disabled, all entries of
sys.path_hooks not related to
OxidizedFinder will be removed.
OxidizedFinder for the Python API documentation.