fix(examples): use filelock to prevent pooch from clobbering files wh…

…en fetching concurrently

ibis/examples/__init__.py

@@ -4,6 +4,8 @@
 import os
 from typing import TYPE_CHECKING, Optional
 
+import filelock
+
 import ibis
 from ibis.common.grounds import Concrete
 
@@ -36,7 +38,11 @@ def fetch(
         table_name: str | None = None,
         backend: BaseBackend | None = None,
     ) -> ir.Table:
-        path = _EXAMPLES.fetch(self.key, progressbar=True)
+        key = self.key
+        # lock to ensure we don't clobber the file if fetched in another
+        # process
+        with filelock.FileLock(f"{key}.lock"):
+            path = _EXAMPLES.fetch(key, progressbar=True)
 
         if backend is None:
             backend = ibis.get_backend()

pyproject.toml

@@ -32,6 +32,7 @@ classifiers = [
 python = "^3.8"
 atpublic = ">=2.3,<5"
 bidict = ">=0.22.1,<1"
+filelock = ">=3.7.0,<4"
 importlib-resources = { version = ">=5,<6", python = "<3.9" }
 multipledispatch = ">=0.6,<1"
 numpy = ">=1,<2"
@@ -110,7 +111,6 @@ ruff = ">=0.0.271,<0.273"
 
 [tool.poetry.group.test.dependencies]
 black = ">=22.1.0,<24"
-filelock = ">=3.7.0,<4"
 hypothesis = ">=6.58.0,<7"
 packaging = ">=21.3,<24"
 pytest = ">=7.0.0,<8"