netCDF Python: How to get the data type of an attribute of a variable?

Question

I am using netCDF4 Python package, I know that getattr() can get the value of the attribute of a variable of a dataset, e.g.

root = Dataset(file_name,'r')
for var in root.variables.values():
    print 'attrs of this variable:',var.ncattrs()
    for attr in var.ncattrs():
    print '<<attr name>> =', attr
    print '<<attr value>> =',getattr(var,attr)

I can get the name/value pair of the attribute successfully through the above code. Now I want to get the data type(int, float, etc.) of the attribute, but I can't find such method/function, does anyone know? I know there is such API in netCDF C package.

Wont python's `type()` function help? – shad0w_wa1k3r Nov 05 '13 at 05:03 — shad0w_wa1k3r, Nov 05 '13 at 05:03

score 2 · Answer 1 · answered Mar 04 '14 at 23:43

nci = netCDF4.Dataset(file_name,'r')
g_attdict = nci.__dict__
for k,v in g_attdict.iteritems():
  print k, type(v)

Sample output:

comment <type 'unicode'>
mooring_site_desc <type 'unicode'>
breakout_id <type 'numpy.int32'>
ending_julian_day_number <type 'numpy.float64'>
long_name <type 'unicode'>  
...

score 1 · Answer 2 · answered Nov 05 '13 at 05:14

1

If you print the variable, the data type will be listed. To get the numpy dtype use the .dtype attribute:

for var in root.variables.values():
    print var
    print var.dtype

answered Nov 05 '13 at 05:14

desired login

1,138
8
15

1

My question is about the data type of the attributes of the variable, not the data type of the variable. – oldnavy Nov 05 '13 at 14:43
In that case, I'm not sure I understand your question. With the netCDF files I normally deal with the attributes are all strings. – desired login Nov 05 '13 at 22:16
I too have this question. Using python NetCDF4 API. Doesn't seem to have this abilty, though Java NetCDF4 does. – Eric Bridger Mar 04 '14 at 22:59
@ashish-nitin-patil was correct. it does. See new answer. – Eric Bridger Mar 04 '14 at 23:24

netCDF Python: How to get the data type of an attribute of a variable?

2 Answers2