switch nclist -> contents; make files click.Path

Author: dwhswenson

paths_cli/commands/contents.py

@@ -2,11 +2,11 @@
 from paths_cli.parameters import INPUT_FILE
 
 @click.command(
-    'nclist',
+    'contents',
     short_help="list named objects from an OPS .nc file",
 )
 @INPUT_FILE.clicked(required=True)
-def nclist(input_file):
+def contents(input_file):
     """List the names of named objects in an OPS .nc file.
 
     This is particularly useful when getting ready to use one of simulation
@@ -63,6 +63,6 @@ def get_section_string_nameable(section, store, get_named):
                     + _item_or_items(n_unnamed))
     return out_str
 
-CLI = nclist
+CLI = contents
 SECTION = "Miscellaneous"
 REQUIRES_OPS = (1, 0)

paths_cli/parameters.py

@@ -182,12 +182,15 @@ def init_snap_fallback(parameter, storage, name):
 )
 
 INPUT_FILE = StorageLoader(
-    param=Argument('input_file', type=str),
+    param=Argument('input_file',
+                   type=click.Path(exists=True, readable=True)),
     mode='r'
 )
 
 OUTPUT_FILE = StorageLoader(
-    param=Option('-o', '--output-file', type=str, help="output ncfile"),
+    param=Option('-o', '--output-file',
+                 type=click.Path(writable=True),
+                 help="output ncfile"),
     mode='w'
 )