Fix mypy errors

Author: alanhdu

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

@@ -9,7 +9,7 @@
 import threading
 from contextlib import contextmanager
 from glob import has_magic
-from typing import Iterable
+from typing import TYPE_CHECKING, Iterable
 
 from .callbacks import _DEFAULT_CALLBACK
 from .exceptions import FSTimeoutError
@@ -157,8 +157,9 @@ def get_loop():
 try:
     import resource
 except ImportError:
-    resource = None
-    ResourceError = OSError
+    if not TYPE_CHECKING:
+        resource = None
+        ResourceError = OSError
 else:
     ResourceError = getattr(resource, "error", IOError)
 

fsspec/config.py

@@ -2,8 +2,9 @@
 import json
 import os
 import warnings
+from typing import Any, Dict
 
-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

@@ -3,6 +3,7 @@
 import logging
 import os
 import re
+from typing import ClassVar, Sequence
 
 import panel as pn
 
@@ -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

@@ -7,6 +7,7 @@
 import tempfile
 import time
 from shutil import rmtree
+from typing import ClassVar, Tuple, Union
 
 from fsspec import AbstractFileSystem, filesystem
 from fsspec.callbacks import _DEFAULT_CALLBACK
@@ -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

@@ -4,6 +4,7 @@
 from datetime import datetime
 from errno import ENOTEMPTY
 from io import BytesIO
+from typing import Any, ClassVar, Dict
 
 from fsspec import AbstractFileSystem
 
@@ -17,7 +18,7 @@ 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

@@ -6,13 +6,15 @@
 import math
 import os
 from functools import lru_cache
+from typing import TYPE_CHECKING
 
 import fsspec.core
 
 try:
     import ujson as json
 except ImportError:
-    import json
+    if not TYPE_CHECKING:
+        import json
 
 from ..asyn import AsyncFileSystem
 from ..callbacks import _DEFAULT_CALLBACK
@@ -803,11 +805,11 @@ 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 = []
@@ -924,7 +926,6 @@ 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)
@@ -939,7 +940,6 @@ 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 @@
 import importlib
 import types
 import warnings
+from typing import Dict, Type
 
 __all__ = ["registry", "get_filesystem_class", "default"]
 
 # internal, mutable
-_registry = {}
+_registry: Dict[str, Type] = {}
 
 # external, immutable
 registry = types.MappingProxyType(_registry)

fsspec/spec.py

@@ -7,6 +7,7 @@
 from errno import ESPIPE
 from glob import has_magic
 from hashlib import sha256
+from typing import ClassVar, Tuple, Union
 
 from .callbacks import _DEFAULT_CALLBACK
 from .config import apply_config, conf
@@ -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

@@ -8,6 +8,7 @@
 from functools import partial
 from hashlib import md5
 from importlib.metadata import version
+from typing import Dict
 from urllib.parse import urlsplit
 
 DEFAULT_BLOCK_SIZE = 5 * 2**20
@@ -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):