cdscan error with Python 3

[zshaheen]

When running a command like this:

cdscan -x test.xml /p/user_pub/work/E3SM/1_0/piControl/1deg_atm_60-30km_ocean/atmos/129x256/model-output/mon/ens1/v1/20180129.DECKv1b_piControl.ne30_oEC.edison.cam.h0*nc

with cdms 3.0 on a Python 3 env, I get the following error:

Finding common directory ...
Common directory: /p/user_pub/work/E3SM/1_0/piControl/1deg_atm_60-30km_ocean/atmos/129x256/model-output/mon/ens1/v1/
Scanning files ...
/p/user_pub/work/E3SM/1_0/piControl/1deg_atm_60-30km_ocean/atmos/129x256/model-output/mon/ens1/v1/20180129.DECKv1b_piControl.ne30_oEC.edison.cam.h0.0001-01.nc
Traceback (most recent call last):
  File "/export/shaheen2/anaconda2/envs/acme_diags_env_dev_py3/bin/cdscan", line 1840, in <module>
    main(sys.argv)
  File "/export/shaheen2/anaconda2/envs/acme_diags_env_dev_py3/bin/cdscan", line 1153, in main
    varnames.append(axisvar.id)
AttributeError: 'dict_keys' object has no attribute 'append'

In Python 3, dict.keys() returns an object of type dict_keys, not a list. All that's needed is to do varnames = list(varnames) before any of the statements using varnames, like the offending line varnames.append(axisvar.id) .

[zshaheen]

This is not an issue with the Python 2 version.

[dnadeau4]

Are you using python3?

[zshaheen]

@dnadeau4 Yes, I believe I was.

[dnadeau4]

found it, there now variables.keys() return a dictionary instead of a list.

[dnadeau4]

cdscan

1134         varnames = list(f.variables.keys())
1135 
1136         # Try to force all axes to be included, but only small ones, length<100.
1137         # This section was motivated by a need to preserve the cloud axes isccp_prs,isccp_tau.
1138         # If we ever need to preserve longer axes as well, we could create one
1139         # variable per axis...

[durack1]

@forsyth2 @jasonb5 this might be another issue that can be closed due to #399?

[jasonb5]

@durack1 This looks like a duplicate. The fix will be included with CDAT 8.2.1. Thanks!