Revert auto_mkdir default in open() and special case local (#1365)

Author: martindurant

fsspec/core.py

@@ -210,6 +210,7 @@ def open_files(
     num=1,
     protocol=None,
     newline=None,
+    auto_mkdir=True,
     expand=True,
     **kwargs,
 ):
@@ -248,6 +249,9 @@ def open_files(
     newline: bytes or None
         Used for line terminator in text mode. If None, uses system default;
         if blank, uses no translation.
+    auto_mkdir: bool (True)
+        If in write mode, this will ensure the target directory exists before
+        writing, by calling ``fs.mkdirs(exist_ok=True)``.
     expand: bool
     **kwargs: dict
         Extra options that make sense to a particular storage connection, e.g.
@@ -284,6 +288,11 @@ def open_files(
         protocol=protocol,
         expand=expand,
     )
+    if fs.protocol == "file":
+        fs.auto_mkdir = auto_mkdir
+    elif "r" not in mode and auto_mkdir:
+        parents = {fs._parent(path) for path in paths}
+        [fs.makedirs(parent, exist_ok=True) for parent in parents]
     return OpenFiles(
         [
             OpenFile(