add get_fill_value Variable method and fill_value='default' option #1375
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jswhit
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jswhit
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| if no_fill == 1: # no filling for this variable | ||
| return None | ||
| else: | ||
| try: | ||
| fillval = self._FillValue | ||
| return fillval |
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I'm not sure when no_fill would be one -- but if there is a _FillValue attribute, maybe it should be returned anyway? e.g. look for that first?
The other question is what to do if the _FillValue attribute doesn't match what nc_inq_var_fill returns?
That would be a malformed file, but maybe helpful to warn the user somehow?
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if no_fill=1, there is no pre-filling of data in the variable (so _FillValue is not used). Not sure what happens if pre-filling is turned off and _FillValue is set - but in this case, I think the user would expect to get information on what is actually happening when you create a variable and don't write data to it.
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Yeah -- that's the challenge -- the fill value has a well defined meaning and purpose, but it's commonly used (abused?) to means missing value, or invalid value. So someone could, in theory, write a file without the fill value set, and then use the attribute to mean missing data. so ????
But I suppose the pathological cases are not our problem :-) -- the point of this new method to get the actual, under the hood, fill_value.
in which case, looking for the FillValue attribute is unnecessary -- unless we want to check that it matches, which might be a good idea!
| _ensure_nc_success(ierr) | ||
| return fillval | ||
| else: | ||
| # no default filling for non-primitive data types. |
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Maybe this is where no_fill would be 1 -- so I'd think we would want to return the _FillValue attribute if it exists.
see issue #1374