Merge pull request #221 from FFY00/use-files-in-leacy-api

Replace legacy API implementation with files()

Author: jaraco

importlib_resources/__init__.py

@@ -3,19 +3,20 @@
 from ._common import (
     as_file,
     files,
-)
-
-from importlib_resources._py3 import (
     Package,
     Resource,
+)
+
+from ._legacy import (
     contents,
-    is_resource,
     open_binary,
-    open_text,
-    path,
     read_binary,
+    open_text,
     read_text,
+    is_resource,
+    path,
 )
+
 from importlib_resources.abc import ResourceReader
 
 

importlib_resources/_adapters.py

@@ -1,4 +1,5 @@
 from contextlib import suppress
+from io import TextIOWrapper
 
 from . import abc
 
@@ -25,32 +26,119 @@ def __init__(self, spec):
         self.spec = spec
 
     def get_resource_reader(self, name):
-        return DegenerateFiles(self.spec)._native()
+        return CompatibilityFiles(self.spec)._native()
 
 
-class DegenerateFiles:
+def _io_wrapper(file, mode='r', *args, **kwargs):
+    if mode == 'r':
+        return TextIOWrapper(file, *args, **kwargs)
+    elif mode == 'rb':
+        return file
+    raise ValueError(
+        "Invalid mode value '{}', only 'r' and 'rb' are supported".format(mode)
+    )
+
+
+class CompatibilityFiles:
     """
     Adapter for an existing or non-existant resource reader
-    to provide a degenerate .files().
+    to provide a compability .files().
     """
 
-    class Path(abc.Traversable):
+    class SpecPath(abc.Traversable):
+        """
+        Path tied to a module spec.
+        Can be read and exposes the resource reader children.
+        """
+
+        def __init__(self, spec, reader):
+            self._spec = spec
+            self._reader = reader
+
+        def iterdir(self):
+            if not self._reader:
+                return iter(())
+            return iter(
+                CompatibilityFiles.ChildPath(self._reader, path)
+                for path in self._reader.contents()
+            )
+
+        def is_file(self):
+            return False
+
+        is_dir = is_file
+
+        def joinpath(self, other):
+            if not self._reader:
+                return CompatibilityFiles.OrphanPath(other)
+            return CompatibilityFiles.ChildPath(self._reader, other)
+
+        @property
+        def name(self):
+            return self._spec.name
+
+        def open(self, mode='r', *args, **kwargs):
+            return _io_wrapper(self._reader.open_resource(None), mode, *args, **kwargs)
+
+    class ChildPath(abc.Traversable):
+        """
+        Path tied to a resource reader child.
+        Can be read but doesn't expose any meaningfull children.
+        """
+
+        def __init__(self, reader, name):
+            self._reader = reader
+            self._name = name
+
         def iterdir(self):
             return iter(())
 
+        def is_file(self):
+            return self._reader.is_resource(self.name)
+
         def is_dir(self):
+            return not self.is_file()
+
+        def joinpath(self, other):
+            return CompatibilityFiles.OrphanPath(self.name, other)
+
+        @property
+        def name(self):
+            return self._name
+
+        def open(self, mode='r', *args, **kwargs):
+            return _io_wrapper(
+                self._reader.open_resource(self.name), mode, *args, **kwargs
+            )
+
+    class OrphanPath(abc.Traversable):
+        """
+        Orphan path, not tied to a module spec or resource reader.
+        Can't be read and doesn't expose any meaningful children.
+        """
+
+        def __init__(self, *path_parts):
+            if len(path_parts) < 1:
+                raise ValueError('Need at least one path part to construct a path')
+            self._path = path_parts
+
+        def iterdir(self):
+            return iter(())
+
+        def is_file(self):
             return False
 
-        is_file = exists = is_dir  # type: ignore
+        is_dir = is_file
 
         def joinpath(self, other):
-            return DegenerateFiles.Path()
+            return CompatibilityFiles.OrphanPath(*self._path, other)
 
+        @property
         def name(self):
-            return ''
+            return self._path[-1]
 
-        def open(self):
-            raise ValueError()
+        def open(self, mode='r', *args, **kwargs):
+            raise FileNotFoundError("Can't open orphan path")
 
     def __init__(self, spec):
         self.spec = spec
@@ -71,7 +159,7 @@ def __getattr__(self, attr):
         return getattr(self._reader, attr)
 
     def files(self):
-        return DegenerateFiles.Path()
+        return CompatibilityFiles.SpecPath(self.spec, self._reader)
 
 
 def wrap_spec(package):

importlib_resources/_common.py

@@ -12,6 +12,7 @@
 from ._compat import wrap_spec
 
 Package = Union[types.ModuleType, str]
+Resource = Union[str, os.PathLike]
 
 
 def files(package):
@@ -93,7 +94,7 @@ def _tempfile(reader, suffix=''):
     finally:
         try:
             os.remove(raw_path)
-        except FileNotFoundError:
+        except (FileNotFoundError, PermissionError):
             pass
 
 

importlib_resources/_compat.py

@@ -61,7 +61,11 @@ def _native_reader(spec):
             return reader if hasattr(reader, 'files') else None
 
         def _file_reader(spec):
-            if pathlib.Path(self.path).exists():
+            try:
+                path = pathlib.Path(self.path)
+            except TypeError:
+                return None
+            if path.exists():
                 return readers.FileReader(self)
 
         return (
@@ -76,7 +80,8 @@ def _file_reader(spec):
             or
             # local FileReader
             _file_reader(self.spec)
-            or _adapters.DegenerateFiles(self.spec)
+            # fallback - adapt the spec ResourceReader to TraversableReader
+            or _adapters.CompatibilityFiles(self.spec)
         )
 
 

importlib_resources/_legacy.py

@@ -0,0 +1,85 @@
+import os
+import pathlib
+import types
+
+from typing import Union, Iterable, ContextManager
+from typing.io import BinaryIO, TextIO
+
+from . import _common
+
+Package = Union[types.ModuleType, str]
+Resource = Union[str, os.PathLike]
+
+
+def open_binary(package: Package, resource: Resource) -> BinaryIO:
+    """Return a file-like object opened for binary reading of the resource."""
+    return (_common.files(package) / _common.normalize_path(resource)).open('rb')
+
+
+def read_binary(package: Package, resource: Resource) -> bytes:
+    """Return the binary contents of the resource."""
+    return (_common.files(package) / _common.normalize_path(resource)).read_bytes()
+
+
+def open_text(
+    package: Package,
+    resource: Resource,
+    encoding: str = 'utf-8',
+    errors: str = 'strict',
+) -> TextIO:
+    """Return a file-like object opened for text reading of the resource."""
+    return (_common.files(package) / _common.normalize_path(resource)).open(
+        'r', encoding=encoding, errors=errors
+    )
+
+
+def read_text(
+    package: Package,
+    resource: Resource,
+    encoding: str = 'utf-8',
+    errors: str = 'strict',
+) -> str:
+    """Return the decoded string of the resource.
+
+    The decoding-related arguments have the same semantics as those of
+    bytes.decode().
+    """
+    with open_text(package, resource, encoding, errors) as fp:
+        return fp.read()
+
+
+def contents(package: Package) -> Iterable[str]:
+    """Return an iterable of entries in `package`.
+
+    Note that not all entries are resources.  Specifically, directories are
+    not considered resources.  Use `is_resource()` on each entry returned here
+    to check if it is a resource or not.
+    """
+    return [path.name for path in _common.files(package).iterdir()]
+
+
+def is_resource(package: Package, name: str) -> bool:
+    """True if `name` is a resource inside `package`.
+
+    Directories are *not* resources.
+    """
+    resource = _common.normalize_path(name)
+    return any(
+        traversable.name == resource and traversable.is_file()
+        for traversable in _common.files(package).iterdir()
+    )
+
+
+def path(
+    package: Package,
+    resource: Resource,
+) -> ContextManager[pathlib.Path]:
+    """A context manager providing a file path object to the resource.
+
+    If the resource does not already exist on its own on the file system,
+    a temporary file will be created. If the file was created, the file
+    will be deleted upon exiting the context manager (no exception is
+    raised if the file was deleted prior to the context manager
+    exiting).
+    """
+    return _common.as_file(_common.files(package) / _common.normalize_path(resource))