[CLIMATE-274] Make the exception that the Dataset class throws more descriptive

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.2-incubating
• Fix Version/s: 0.3-incubating
• Component/s: data sources, general

Environment

OS X

• Assignee: Cameron Goodale
• Reporter: Cameron Goodale
• Due: 22/Aug/13
• Created: 22/Aug/13 14:02
• Updated: 26/Aug/13 16:31
• Resolved: 26/Aug/13 16:31

Description

When a new Dataset Object is initialized the parameters that are required (4 total) are all checked individually as well as together, and if any of these tests fail a ValueError is raised with the following message to the user:
"Dataset given improperly shaped array during initialization."

I would like to try and make that error message more specific about which one of the checks raised the error.

Example Messages:
--------------------------------

• Longitude Array is not 1 dimension
• Latitude Array is not 1 dimension
• Times Array is not 1 dimension
• Times Array doesn't contain datetime objects
• Values Arrays is not 3 dimensional
• Values Array is out of order. Expected (times, lat, lon) but got ([what ever we discovered] lon, times, lat)

To some people this amount of check and rigor might seem overkill, but I think this is necessary since the rest of the OCW code depends on have a properly formed OCW Dataset object to work with.