|
7 | 7 | .. automethod:: load.as_path |
8 | 8 |
|
9 | 9 | .. automethod:: load.cached |
10 | | -
|
11 | | -.. autoclass:: Loader |
12 | 10 | """ |
13 | | -from __future__ import annotations |
14 | | - |
15 | | -import atexit |
16 | | -import os |
17 | | -from contextlib import AbstractContextManager, ExitStack |
18 | | -from functools import cached_property |
19 | | -from pathlib import Path |
20 | | -from types import ModuleType |
21 | | -from typing import Union |
22 | | - |
23 | | -try: |
24 | | - from functools import cache |
25 | | -except ImportError: # PY38 |
26 | | - from functools import lru_cache as cache |
27 | | - |
28 | | -try: # Prefer backport to leave consistency to dependency spec |
29 | | - from importlib_resources import as_file, files |
30 | | -except ImportError: |
31 | | - from importlib.resources import as_file, files # type: ignore |
32 | | - |
33 | | -try: # Prefer stdlib so Sphinx can link to authoritative documentation |
34 | | - from importlib.resources.abc import Traversable |
35 | | -except ImportError: |
36 | | - from importlib_resources.abc import Traversable |
37 | | - |
38 | | -__all__ = ["load"] |
39 | | - |
40 | | - |
41 | | -class Loader: |
42 | | - """A loader for package files relative to a module |
43 | | -
|
44 | | - This class wraps :mod:`importlib.resources` to provide a getter |
45 | | - function with an interpreter-lifetime scope. For typical packages |
46 | | - it simply passes through filesystem paths as :class:`~pathlib.Path` |
47 | | - objects. For zipped distributions, it will unpack the files into |
48 | | - a temporary directory that is cleaned up on interpreter exit. |
49 | | -
|
50 | | - This loader accepts a fully-qualified module name or a module |
51 | | - object. |
52 | | -
|
53 | | - Expected usage:: |
54 | | -
|
55 | | - '''Data package |
56 | | -
|
57 | | - .. autofunction:: load_data |
58 | | -
|
59 | | - .. automethod:: load_data.readable |
60 | | -
|
61 | | - .. automethod:: load_data.as_path |
62 | | -
|
63 | | - .. automethod:: load_data.cached |
64 | | - ''' |
65 | | -
|
66 | | - from niworkflows.data import Loader |
67 | | -
|
68 | | - load_data = Loader(__package__) |
69 | | -
|
70 | | - :class:`~Loader` objects implement the :func:`callable` interface |
71 | | - and generate a docstring, and are intended to be treated and documented |
72 | | - as functions. |
73 | | -
|
74 | | - For greater flexibility and improved readability over the ``importlib.resources`` |
75 | | - interface, explicit methods are provided to access resources. |
76 | | -
|
77 | | - +---------------+----------------+------------------+ |
78 | | - | On-filesystem | Lifetime | Method | |
79 | | - +---------------+----------------+------------------+ |
80 | | - | `True` | Interpreter | :meth:`cached` | |
81 | | - +---------------+----------------+------------------+ |
82 | | - | `True` | `with` context | :meth:`as_path` | |
83 | | - +---------------+----------------+------------------+ |
84 | | - | `False` | n/a | :meth:`readable` | |
85 | | - +---------------+----------------+------------------+ |
86 | | -
|
87 | | - It is also possible to use ``Loader`` directly:: |
88 | | -
|
89 | | - from niworkflows.data import Loader |
90 | | -
|
91 | | - Loader(other_package).readable('data/resource.ext').read_text() |
92 | | -
|
93 | | - with Loader(other_package).as_path('data') as pkgdata: |
94 | | - # Call function that requires full Path implementation |
95 | | - func(pkgdata) |
96 | | -
|
97 | | - # contrast to |
98 | | -
|
99 | | - from importlib_resources import files, as_file |
100 | | -
|
101 | | - files(other_package).joinpath('data/resource.ext').read_text() |
102 | | -
|
103 | | - with as_file(files(other_package) / 'data') as pkgdata: |
104 | | - func(pkgdata) |
105 | | -
|
106 | | - .. automethod:: readable |
107 | | -
|
108 | | - .. automethod:: as_path |
109 | | -
|
110 | | - .. automethod:: cached |
111 | | - """ |
112 | | - |
113 | | - def __init__(self, anchor: Union[str, ModuleType]): |
114 | | - self._anchor = anchor |
115 | | - self.files = files(anchor) |
116 | | - self.exit_stack = ExitStack() |
117 | | - atexit.register(self.exit_stack.close) |
118 | | - # Allow class to have a different docstring from instances |
119 | | - self.__doc__ = self._doc |
120 | | - |
121 | | - @cached_property |
122 | | - def _doc(self): |
123 | | - """Construct docstring for instances |
124 | | -
|
125 | | - Lists the public top-level paths inside the location, where |
126 | | - non-public means has a `.` or `_` prefix or is a 'tests' |
127 | | - directory. |
128 | | - """ |
129 | | - top_level = sorted( |
130 | | - os.path.relpath(p, self.files) + "/"[: p.is_dir()] |
131 | | - for p in self.files.iterdir() |
132 | | - if p.name[0] not in (".", "_") and p.name != "tests" |
133 | | - ) |
134 | | - doclines = [ |
135 | | - f"Load package files relative to ``{self._anchor}``.", |
136 | | - "", |
137 | | - "This package contains the following (top-level) files/directories:", |
138 | | - "", |
139 | | - *(f"* ``{path}``" for path in top_level), |
140 | | - ] |
141 | | - |
142 | | - return "\n".join(doclines) |
143 | | - |
144 | | - def readable(self, *segments) -> Traversable: |
145 | | - """Provide read access to a resource through a Path-like interface. |
146 | | -
|
147 | | - This file may or may not exist on the filesystem, and may be |
148 | | - efficiently used for read operations, including directory traversal. |
149 | | -
|
150 | | - This result is not cached or copied to the filesystem in cases where |
151 | | - that would be necessary. |
152 | | - """ |
153 | | - return self.files.joinpath(*segments) |
154 | | - |
155 | | - def as_path(self, *segments) -> AbstractContextManager[Path]: |
156 | | - """Ensure data is available as a :class:`~pathlib.Path`. |
157 | | -
|
158 | | - This method generates a context manager that yields a Path when |
159 | | - entered. |
160 | | -
|
161 | | - This result is not cached, and any temporary files that are created |
162 | | - are deleted when the context is exited. |
163 | | - """ |
164 | | - return as_file(self.files.joinpath(*segments)) |
165 | | - |
166 | | - @cache |
167 | | - def cached(self, *segments) -> Path: |
168 | | - """Ensure data is available as a :class:`~pathlib.Path`. |
169 | | -
|
170 | | - Any temporary files that are created remain available throughout |
171 | | - the duration of the program, and are deleted when Python exits. |
172 | | -
|
173 | | - Results are cached so that multiple calls do not unpack the same |
174 | | - data multiple times, but the cache is sensitive to the specific |
175 | | - argument(s) passed. |
176 | | - """ |
177 | | - return self.exit_stack.enter_context(as_file(self.files.joinpath(*segments))) |
178 | | - |
179 | | - __call__ = cached |
180 | 11 |
|
| 12 | +from acres import Loader |
181 | 13 |
|
182 | 14 | load = Loader(__package__) |
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