Python 3.8 compatibility (#194)

* Python 3.8 compatibility

* files for Travis CI

* Added py27 compatibility

Co-authored-by: Uchida Takaya <takachanbo@meom-dyn109.obs.ujf-grenoble.fr>

.travis.yml

@@ -13,6 +13,10 @@ matrix:
     env: CONDA_ENV=py36
   - python: 3.6
     env: CONDA_ENV=py36-xarraymaster
+  - python: 3.7
+    env: CONDA_ENV=py37
+  - python: 3.8
+    env: CONDA_ENV=py38
 
 before_install:
   - if [[ "$TRAVIS_PYTHON_VERSION" == "2.7" ]]; then

ci/environment-py37.yml

@@ -0,0 +1,17 @@
+name: test_env
+channels:
+  - conda-forge
+dependencies:
+  - python=3.7
+  - xarray
+  - dask
+  - numpy
+  - pytest
+  - future
+  - zarr
+  - cftime
+  - pip:
+    - cachetools
+    - fsspec
+    - codecov
+    - pytest-cov

ci/environment-py38.yml

@@ -0,0 +1,17 @@
+name: test_env
+channels:
+  - conda-forge
+dependencies:
+  - python=3.8
+  - xarray
+  - dask
+  - numpy
+  - pytest
+  - future
+  - zarr
+  - cftime
+  - pip:
+    - cachetools
+    - fsspec
+    - codecov
+    - pytest-cov

setup.py

@@ -19,17 +19,17 @@
     'Intended Audience :: Science/Research',
     'Programming Language :: Python',
     'Programming Language :: Python :: 2',
-    'Programming Language :: Python :: 2.6',
     'Programming Language :: Python :: 2.7',
     'Programming Language :: Python :: 3',
-    'Programming Language :: Python :: 3.3',
-    'Programming Language :: Python :: 3.4',
+    'Programming Language :: Python :: 3.6',
+    'Programming Language :: Python :: 3.7',
+    'Programming Language :: Python :: 3.8',
     'Topic :: Scientific/Engineering',
 ]
 
-INSTALL_REQUIRES = ['xarray >= 0.10.1', 'dask >= 0.12', 'cachetools']
+INSTALL_REQUIRES = ['xarray >= 0.10.1', 'dask >= 1.0', 'cachetools']
 SETUP_REQUIRES = ['pytest-runner']
-TESTS_REQUIRE = ['pytest >= 2.8', 'coverage']
+TESTS_REQUIRE = ['pytest >= 4.0', 'coverage']
 
 DESCRIPTION = "Read MITgcm mds binary files into xarray"
 def readme():

xmitgcm/mds_store.py

@@ -233,7 +233,10 @@ def open_mdsdataset(data_dir, grid_dir=None,
                                     for coord in ['k', 'k_l', 'k_u', 'k_p1']})
                     datasets.insert(0, grid_dataset)
                 # apply chunking
-                ds = xr.auto_combine(datasets)
+                if sys.version_info[0] < 3:
+                    ds = xr.auto_combine(datasets)
+                else:
+                    ds = xr.combine_by_coords(datasets)
                 if swap_dims:
                     ds = _swap_dimensions(ds, geometry)
                 if grid_vars_to_coords:
@@ -311,9 +314,12 @@ def _swap_dimensions(ds, geometry, drop_old=True):
     for orig_dim in ds.dims:
         if 'swap_dim' in ds[orig_dim].attrs:
             new_dim = ds[orig_dim].attrs['swap_dim']
-            ds = ds.swap_dims({orig_dim: new_dim})
+            ds = ds.swap_dims({orig_dim:  new_dim})
             if drop_old:
-                ds = ds.drop(orig_dim)
+                if sys.version_info[0] < 3:
+                    ds = ds.drop(orig_dim)
+                else:
+                    ds = ds.drop_vars(orig_dim)
     return ds