feat(query): query to csv skip empty lines

[bednar]

Closes #533

Proposed Changes

The querying into CSV skip empty lines from InfluxDB response.

#datatype,string,long,dateTime:RFC3339,double,string
#group,false,false,false,false,true
#default,_result,,,,
,result,table,_time,_value,_field
,,0,2022-11-24T10:00:10Z,0.1,_1_current_(mA)
,,1,2022-11-24T10:00:10Z,4,_1_current_limit_(mA)
,,2,2022-11-24T10:00:10Z,1,_1_voltage_(V)
,,3,2022-11-24T10:00:10Z,1,_1_voltage_limit_(V)
,,4,2022-11-24T10:00:10Z,0,_2_current_(mA)
,,5,2022-11-24T10:00:10Z,0,_2_current_limit_(mA)
,,6,2022-11-24T10:00:10Z,0,_2_voltage_(V)
,,7,2022-11-24T10:00:10Z,0,_2_voltage_limit_(V)

#datatype,string,long,dateTime:RFC3339,string,string
#group,false,false,false,false,true
#default,_result,,,,
,result,table,_time,_value,_field
,,8,2022-11-24T10:00:10Z,K,type
,,9,2022-11-24T10:00:10Z,,type2

is parsed as:

['#group', 'false', 'false', 'false', 'false', 'true']
['#default', '_result', '', '', '', '']
['', 'result', 'table', '_time', '_value', '_field']
['', '', '0', '2022-11-24T10:00:10Z', '0.1', '_1_current_(mA)']
['', '', '1', '2022-11-24T10:00:10Z', '4', '_1_current_limit_(mA)']
['', '', '2', '2022-11-24T10:00:10Z', '1', '_1_voltage_(V)']
['', '', '3', '2022-11-24T10:00:10Z', '1', '_1_voltage_limit_(V)']
['', '', '4', '2022-11-24T10:00:10Z', '0', '_2_current_(mA)']
['', '', '5', '2022-11-24T10:00:10Z', '0', '_2_current_limit_(mA)']
['', '', '6', '2022-11-24T10:00:10Z', '0', '_2_voltage_(V)']
['', '', '7', '2022-11-24T10:00:10Z', '0', '_2_voltage_limit_(V)']
['#datatype', 'string', 'long', 'dateTime:RFC3339', 'string', 'string']
['#group', 'false', 'false', 'false', 'false', 'true']
['#default', '_result', '', '', '', '']
['', 'result', 'table', '_time', '_value', '_field']
['', '', '8', '2022-11-24T10:00:10Z', 'K', 'type']
['', '', '9', '2022-11-24T10:00:10Z', '', 'type2']

not as:

['#datatype', 'string', 'long', 'dateTime:RFC3339', 'double', 'string']
['#group', 'false', 'false', 'false', 'false', 'true']
['#default', '_result', '', '', '', '']
['', 'result', 'table', '_time', '_value', '_field']
['', '', '0', '2022-11-24T10:00:10Z', '0.1', '_1_current_(mA)']
['', '', '1', '2022-11-24T10:00:10Z', '4', '_1_current_limit_(mA)']
['', '', '2', '2022-11-24T10:00:10Z', '1', '_1_voltage_(V)']
['', '', '3', '2022-11-24T10:00:10Z', '1', '_1_voltage_limit_(V)']
['', '', '4', '2022-11-24T10:00:10Z', '0', '_2_current_(mA)']
['', '', '5', '2022-11-24T10:00:10Z', '0', '_2_current_limit_(mA)']
['', '', '6', '2022-11-24T10:00:10Z', '0', '_2_voltage_(V)']
['', '', '7', '2022-11-24T10:00:10Z', '0', '_2_voltage_limit_(V)']
[]
[]
['#datatype', 'string', 'long', 'dateTime:RFC3339', 'string', 'string']
['#group', 'false', 'false', 'false', 'false', 'true']
['#default', '_result', '', '', '', '']
['', 'result', 'table', '_time', '_value', '_field']
['', '', '8', '2022-11-24T10:00:10Z', 'K', 'type']
['', '', '9', '2022-11-24T10:00:10Z', '', 'type2']
[]

Checklist

• CHANGELOG.md updated
• Rebased/mergeable
• A test has been added if appropriate
• pytest tests completes successfully
• Commit messages are conventional
• Sign CLA (if not already signed)

[powersj]

Current users probably have logic in place to avoid these lines, my only concern is if someone is counting on these being there to do some sort of parsing or counting. Overall though, this is an improvement over the current state.

[bednar]

I don't think there's anyone who relies on empty CSV row. From my POV it is a bug.