Dod example (#640)

* BUG: Bug fix for when it's not a standard ARM file

* ENH:  Updating to be more robust

* ADD: Adding new example on how to create datasets based on ARM DODs and modify attributes

* ENH: PEP8 issue

examples/io/plot_create_arm_ds.py

@@ -0,0 +1,55 @@
+"""
+Create a dataset to mimic ARM file formats
+------------------------------------------
+Example shows how to create a dataset from an ARM DOD.
+This will enable users to create files that mimic ARM
+files, making for easier use across the community.
+
+Author: Adam Theisen
+
+"""
+
+import act
+
+# Create an empty dataset using an ARM DOD
+ds = act.io.armfiles.create_ds_from_arm_dod('vdis.b1', {'time': 1440}, scalar_fill_dim='time')
+
+# Print out the xarray dataset to see that it's empty
+print(ds)
+
+# The user could populate this through a number of ways
+# and that's best left up to the user on how to do it.
+# If one has an existing dataset, a mapping of variable
+# names is sometimes the easiest way
+
+# Let's look at some variable attributes
+# These can be updated and it would be up to the
+# user to ensure these tests are being applied
+# and are appropriately set in the cooresponding QC variable
+print(ds['num_drops'].attrs)
+
+# Next, let's print out the global attribuets
+print(ds.attrs)
+
+# Add additional attributes or append to existing
+# if they are needed using a dictionary
+atts = {
+    'command_line': 'python  plot_create_arm_ds.py',
+    'process_version': '1.2.3',
+    'history': 'Processed with Jupyter Workbench',
+    'random': '1234253sdgfadf'
+}
+for a in atts:
+    if a in ds.attrs:
+        ds.attrs[a] += atts[a]
+    else:
+        ds.attrs[a] = atts[a]
+    # Print out the attribute
+    print(a, ds.attrs[a])
+
+# Write data out to netcdf
+ds.to_netcdf('./sgpvdisX1.b1.20230101.000000.nc')
+
+# If one wants to clean up the dataset to better match CF standards
+# the following can be done as well
+ds.write.write_netcdf(cf_compliant=True, path='./sgpvdisX1.b1.20230101.000000.cf')