[tune] Remove py2.7-specific code (#6665)

* Remove backwards compatability py2.7 code.

* Use exists_ok=True in ray

* nit

* nit

Co-authored-by: Richard Liaw <rliaw@berkeley.edu>

python/ray/utils.py

@@ -545,26 +545,14 @@ def try_make_directory_shared(directory_path):
             raise
 
 
-def try_to_create_directory(directory_path, warn_if_exist=True):
+def try_to_create_directory(directory_path):
     """Attempt to create a directory that is globally readable/writable.
 
     Args:
         directory_path: The path of the directory to create.
-        warn_if_exist (bool): Warn if the directory already exists.
     """
     directory_path = os.path.expanduser(directory_path)
-    if not os.path.exists(directory_path):
-        try:
-            os.makedirs(directory_path)
-        except OSError as e:
-            if e.errno != errno.EEXIST:
-                raise e
-            if warn_if_exist:
-                logger = logging.getLogger("ray")
-                logger.warning(
-                    "Attempted to create '{}', but the directory already "
-                    "exists.".format(directory_path))
-
+    os.makedirs(directory_path, exist_ok=True)
     # Change the log directory permissions so others can use it. This is
     # important when multiple people are using the same machine.
     try_make_directory_shared(directory_path)