fix: #10628 expanduser path in TrainingArguments (#10660)

* fix: #10628 expanduser path in TrainingArguments

* docs: explain why we expand paths in TrainingArguments

* Style
Co-authored-by: Sylvain Gugger <sylvain.gugger@gmail.com>

src/transformers/training_args.py

@@ -507,6 +507,14 @@ class TrainingArguments:
     _n_gpu: int = field(init=False, repr=False, default=-1)
 
     def __post_init__(self):
+        # expand paths, if not os.makedirs("~/bar") will make directory
+        # in the current directory instead of the actual home
+        #  see https://github.com/huggingface/transformers/issues/10628
+        if self.output_dir is not None:
+            self.output_dir = os.path.expanduser(self.output_dir)
+        if self.logging_dir is not None:
+            self.logging_dir = os.path.expanduser(self.logging_dir)
+
         if self.disable_tqdm is None:
             self.disable_tqdm = logger.getEffectiveLevel() > logging.WARN