bits (#1828)

- make existence of entrypoints optional (for pyscript)
- rename to asyncwrapper for use with URL chaining
- add "pyscript:" known implementation

Author: martindurant

docs/source/api.rst

@@ -237,6 +237,7 @@ documentation carefully before using any particular package.
 - `p9fs`_ for 9P (Plan 9 Filesystem Protocol) servers
 - `PyAthena`_ for S3 access to Amazon Athena, with protocol "s3://" or "s3a://"
 - `PyDrive2`_ for Google Drive access
+- `fsspec-proxy`_ for "pyscript:" URLs via a proxy server
 - `s3fs`_ for Amazon S3 and other compatible stores, with protocol "s3://"
 - `sshfs`_ for access to SSH servers, with protocol "ssh://" or "sftp://"
 - `swiftspec`_ for OpenStack SWIFT, with protocol "swift://"
@@ -254,6 +255,7 @@ documentation carefully before using any particular package.
 .. _dropbox: https://github.com/fsspec/dropboxdrivefs
 .. _dvc: https://github.com/iterative/dvc
 .. _fsspec-encrypted: https://github.com/thevgergroup/fsspec-encrypted
+.. _fsspec-proxy: https://github.com/fsspec/fsspec-proxy
 .. _gcsfs: https://gcsfs.readthedocs.io/en/latest/
 .. _gdrive: https://github.com/fsspec/gdrivefs
 .. _git: https://github.com/iterative/scmrepo

fsspec/__init__.py

@@ -1,5 +1,3 @@
-from importlib.metadata import entry_points
-
 from . import caching
 from ._version import __version__  # noqa: F401
 from .callbacks import Callback
@@ -38,6 +36,10 @@
 
 
 def process_entries():
+    try:
+        from importlib.metadata import entry_points
+    except ImportError:
+        return
     if entry_points is not None:
         try:
             eps = entry_points()

fsspec/implementations/asyn_wrapper.py

@@ -2,6 +2,7 @@
 import functools
 import inspect
 
+import fsspec
 from fsspec.asyn import AsyncFileSystem, running_async
 
 
@@ -42,14 +43,24 @@ class AsyncFileSystemWrapper(AsyncFileSystem):
         The synchronous filesystem instance to wrap.
     """
 
-    protocol = "async_wrapper"
+    protocol = "asyncwrapper", "async_wrapper"
     cachable = False
 
-    def __init__(self, fs, *args, asynchronous=None, **kwargs):
+    def __init__(
+        self,
+        fs=None,
+        asynchronous=None,
+        target_protocol=None,
+        target_options=None,
+        **kwargs,
+    ):
         if asynchronous is None:
             asynchronous = running_async()
-        super().__init__(*args, asynchronous=asynchronous, **kwargs)
-        self.sync_fs = fs
+        super().__init__(asynchronous=asynchronous, **kwargs)
+        if fs is not None:
+            self.sync_fs = fs
+        else:
+            self.sync_fs = fsspec.filesystem(target_protocol, **target_options)
         self.protocol = self.sync_fs.protocol
         self._wrap_all_sync_methods()
 

fsspec/registry.py

@@ -72,13 +72,13 @@ def register_implementation(name, cls, clobber=False, errtxt=None):
         "class": "fsspec.implementations.arrow.HadoopFileSystem",
         "err": "pyarrow and local java libraries required for HDFS",
     },
-    "async_wrapper": {
-        "class": "fsspec.asyn_wrapper.AsyncWrapperFileSystem",
-    },
     "asynclocal": {
         "class": "morefs.asyn_local.AsyncLocalFileSystem",
         "err": "Install 'morefs[asynclocalfs]' to use AsyncLocalFileSystem",
     },
+    "asyncwrapper": {
+        "class": "fsspec.implementations.asyn_wrapper.AsyncFileSystemWrapper",
+    },
     "az": {
         "class": "adlfs.AzureBlobFileSystem",
         "err": "Install adlfs to access Azure Datalake Gen2 and Azure Blob Storage",
@@ -180,6 +180,10 @@ def register_implementation(name, cls, clobber=False, errtxt=None):
         "class": "ossfs.OSSFileSystem",
         "err": "Install ossfs to access Alibaba Object Storage System",
     },
+    "pyscript": {
+        "class": "pyscript_fsspec_client.client.PyscriptFileSystem",
+        "err": "Install requests (cpython) or run in pyscript",
+    },
     "reference": {"class": "fsspec.implementations.reference.ReferenceFileSystem"},
     "root": {
         "class": "fsspec_xrootd.XRootDFileSystem",