Fix mypy errors

fsspec/_version.py

@@ -51,7 +51,6 @@ class NotThisMethod(Exception):
     """Exception raised if a method is not valid for the current scenario."""
 
 
-LONG_VERSION_PY = {}
 HANDLERS = {}
 
 

fsspec/asyn.py

@@ -1,3 +1,4 @@
+from typing import TYPE_CHECKING
 import asyncio
 import asyncio.events
 import functools
@@ -151,8 +152,9 @@ def get_loop():
 try:
     import resource
 except ImportError:
-    resource = None
-    ResourceError = OSError
+    if not TYPE_CHECKING:
+        resource = None
+        ResourceError = OSError
 else:
     ResourceEror = resource.error
 

fsspec/config.py

@@ -1,9 +1,10 @@
+from typing import Any, Dict
 import configparser
 import json
 import os
 import warnings
 
-conf = {}
+conf: Dict[str, Dict[str, Any]] = {}
 default_conf_dir = os.path.join(os.path.expanduser("~"), ".config/fsspec")
 conf_dir = os.environ.get("FSSPEC_CONFIG_DIR", default_conf_dir)
 

fsspec/gui.py

@@ -1,3 +1,4 @@
+from typing import ClassVar, Sequence
 import ast
 import contextlib
 import logging
@@ -25,9 +26,11 @@ class SigSlot(object):
     By default, all signals emit a DEBUG logging statement.
     """
 
-    signals = []  # names of signals that this class may emit
-    # each of which must be set by _register for any new instance
-    slots = []  # names of actions that this class may respond to
+    # names of signals that this class may emit each of which must be
+    # set by _register for any new instance
+    signals: ClassVar[Sequence[str]] = []
+    # names of actions that this class may respond to
+    slots: ClassVar[Sequence[str]] = []
 
     # each of which must be a method name
 

fsspec/implementations/cached.py

@@ -1,3 +1,4 @@
+from typing import ClassVar, Union, Tuple
 import contextlib
 import hashlib
 import inspect
@@ -39,7 +40,7 @@ class CachingFileSystem(AbstractFileSystem):
       allowed, for testing
     """
 
-    protocol = ("blockcache", "cached")
+    protocol: ClassVar[Union[str, Tuple[str, ...]]] = ("blockcache", "cached")
 
     def __init__(
         self,

fsspec/implementations/memory.py

@@ -1,5 +1,7 @@
 from __future__ import absolute_import, division, print_function
 
+from typing import Any, ClassVar, Dict
+
 import logging
 from datetime import datetime
 from errno import ENOTEMPTY
@@ -17,7 +19,7 @@ class MemoryFileSystem(AbstractFileSystem):
     in memory filesystem.
     """
 
-    store = {}  # global, do not overwrite!
+    store: ClassVar[Dict[str, Any]] = {}  # global, do not overwrite!
     pseudo_dirs = [""]  # global, do not overwrite!
     protocol = "memory"
     root_marker = "/"

fsspec/implementations/reference.py

@@ -1,3 +1,4 @@
+from typing import TYPE_CHECKING
 import base64
 import collections
 import io
@@ -12,7 +13,8 @@
 try:
     import ujson as json
 except ImportError:
-    import json
+    if not TYPE_CHECKING:
+        import json
 
 from ..asyn import AsyncFileSystem
 from ..callbacks import _DEFAULT_CALLBACK
@@ -802,11 +804,11 @@ def cat(self, path, recursive=False, on_error="raise", **kwargs):
                     urls.append(u)
                     starts.append(s)
                     ends.append(e)
-                except FileNotFoundError as e:
+                except FileNotFoundError as err:
                     if on_error == "raise":
                         raise
                     if on_error != "omit":
-                        out[p] = e
+                        out[p] = err
 
             # process references into form for merging
             urls2 = []
@@ -923,7 +925,6 @@ def _render_jinja(u):
         self.references.update(self._process_gen(references.get("gen", [])))
 
     def _process_templates(self, tmp):
-
         self.templates = {}
         if self.template_overrides is not None:
             tmp.update(self.template_overrides)
@@ -938,7 +939,6 @@ def _process_templates(self, tmp):
                 self.templates[k] = v
 
     def _process_gen(self, gens):
-
         out = {}
         for gen in gens:
             dimension = {

fsspec/implementations/tar.py

@@ -81,7 +81,7 @@ def __init__(
 
         self._fo_ref = fo
         self.fo = fo  # the whole instance is a context
-        self.tar: tarfile.TarFile = tarfile.TarFile(fileobj=self.fo)
+        self.tar = tarfile.TarFile(fileobj=self.fo)
         self.dir_cache = None
 
         self.index_store = index_store

fsspec/registry.py

@@ -1,11 +1,12 @@
+from typing import Dict, Type
 import importlib
 import types
 import warnings
 
 __all__ = ["registry", "get_filesystem_class", "default"]
 
 # internal, mutable
-_registry = {}
+_registry: Dict[str, Type] = {}
 
 # external, immutable
 registry = types.MappingProxyType(_registry)

fsspec/spec.py

@@ -1,3 +1,4 @@
+from typing import Union, Tuple, ClassVar
 import io
 import logging
 import os
@@ -101,7 +102,7 @@ class AbstractFileSystem(metaclass=_Cached):
     _cached = False
     blocksize = 2**22
     sep = "/"
-    protocol = "abstract"
+    protocol: ClassVar[Union[str, Tuple[str, ...]]] = "abstract"
     _latest = None
     async_impl = False
     mirror_sync_methods = False

fsspec/utils.py

@@ -1,3 +1,4 @@
+from typing import Dict
 import logging
 import math
 import os
@@ -110,7 +111,7 @@ def update_storage_options(options, inherited=None):
 
 
 # Compression extensions registered via fsspec.compression.register_compression
-compressions = {}
+compressions: Dict[str, str] = {}
 
 
 def infer_compression(filename):