Expand user dir paths (~) in open_mfdataset and to_zarr. (#4795)

* Normalize wildcard paths in open_mfdataset.

* Document normalized mfdataset paths in what's new.

* Also normalize paths in to_zarr.

doc/whats-new.rst

@@ -75,6 +75,9 @@ Bug fixes
 - Add ``missing_dims`` parameter to transpose (:issue:`4647`, :pull:`4767`). By `Daniel Mesejo <https://github.com/mesejo>`_.
 - Resolve intervals before appending other metadata to labels when plotting (:issue:`4322`, :pull:`4794`).
   By `Justus Magin <https://github.com/keewis>`_.
+- Expand user directory paths (e.g. ``~/``) in :py:func:`open_mfdataset` and
+  :py:meth:`Dataset.to_zarr` (:issue:`4783`, :pull:`4795`).
+  By `Julien Seguinot <https://github.com/juseg>`_.
 
 Documentation
 ~~~~~~~~~~~~~

xarray/backends/api.py

@@ -887,7 +887,7 @@ def open_mfdataset(
                     paths
                 )
             )
-        paths = sorted(glob(paths))
+        paths = sorted(glob(_normalize_path(paths)))
     else:
         paths = [str(p) if isinstance(p, Path) else p for p in paths]
 
@@ -1386,10 +1386,11 @@ def to_zarr(
 
     See `Dataset.to_zarr` for full API docs.
     """
-    if isinstance(store, Path):
-        store = str(store)
-    if isinstance(chunk_store, Path):
-        chunk_store = str(store)
+
+    # expand str and Path arguments
+    store = _normalize_path(store)
+    chunk_store = _normalize_path(chunk_store)
+
     if encoding is None:
         encoding = {}
 
@@ -1419,9 +1420,6 @@ def to_zarr(
             "compute=False before writing data."
         )
 
-    if isinstance(store, Path):
-        store = str(store)
-
     # validate Dataset keys, DataArray names, and attr keys/values
     _validate_dataset_names(dataset)
     _validate_attrs(dataset)