LineType points to default value for certain line types

[abodh]

Not sure if this an issue with the dss_capi but when I ran some tests, specifically 4 LineTypes are not recognized in altdss when reading a dss file: swt_sect, swt_rec, swt_disc, and swt_brk. Rest of the types seem to be fine.

I installed the package via altdss[all] but here the specific version of associated packages in my environment:

• altdss 0.2.4
• dss-python 0.15.7
• dss-python-backend 0.14.5
• opendssdirect-py 0.9.4

Minimal example below:

Working Examples

 ------- WORKING EXAMPLES -------
New Line.line_1 Phases=3 Bus1="101.1.2.3" Bus2="102.1.2.3" LineType=OH
> altdss.Line['line_1'].LineType_str
> 'oh'

New Line.line_1 Phases=3 Bus1="101.1.2.3" Bus2="102.1.2.3" LineType=UG
> altdss.Line['line_1'].LineType_str
> 'ug'

New Line.switch_1 Phases=3 Bus1="101.1.2.3" Bus2="102.1.2.3" switch="y" LineType=SWT_FUSE
> altdss.Line['switch_1'].LineType_str
> 'swt_fuse'

New Line.switch_1 Phases=3 Bus1="101.1.2.3" Bus2="102.1.2.3" switch="y" LineType=SWT_ELBOW
> altdss.Line['switch_1'].LineType_str
> 'swt_elbow'

Not Working Examples

New Line.switch_1 Phases=3 Bus1="101.1.2.3" Bus2="102.1.2.3" switch="y" LineType=SWT_SECT
> altdss.Line['switch_1'].LineType_str
> 'oh'

New Line.switch_1 Phases=3 Bus1="101.1.2.3" Bus2="102.1.2.3" switch="y" LineType=SWT_REC
> altdss.Line['switch_1'].LineType_str
> 'oh'

New Line.switch_1 Phases=3 Bus1="101.1.2.3" Bus2="102.1.2.3" switch="y" LineType=SWT_DISC
> altdss.Line['switch_1'].LineType_str
> 'oh'

New Line.switch_1 Phases=3 Bus1="101.1.2.3" Bus2="102.1.2.3" switch="y" LineType=SWT_BRK
> altdss.Line['switch_1'].LineType_str
> 'oh'

---

The following confuses me though, if I reassign the LineType_str as one of the non working LineType_str then it still does not work but assigning the LineType value works. Example below:

# assigning the line type string as 'swt_sect' does not work (as discussed above)
> altdss.Line['switch_1'].LineType_str = 'swt_sect'
> altdss.Line['switch_1'].LineType_str
> 'oh'

# assigning the line type as swt_sect int enum works
> altdss.Line['switch_1'].LineType = 7
> altdss.Line['switch_1'].LineType
> <LineType.swt_sect: 7>

> altdss.Line['switch_1'].LineType_str
> 'swt_sect'

At first, I thought anything with swt_ does not work but that is not the case. swt_ldbrk, swt_fuse, and swt_elbow are properly recognized. Similarly, rest of the linetypes are properly recognized as well.

[PMeira]

Thanks for the report! I can confirm it's wonky and nobody reported it before. It seems to be a simple off-by-one error in the specification of the enum in the Pascal/engine code -- from a quick test, that was enough to fix what you listed, but we'll add a full test before the next release (let's keep this open till then).

For further context, the Python LineType_str property is nearly the same as setting the property through a DSS command, while the LineType integer property bypasses any string and sets the internal integer value directly, hence much faster and preferred for performance-sensitive scenarios. Avoid using magic numbers such as 7 though (the value may change across versions), use the provided Python enums instead (e.g. from altdss import LineType as LT; l.LineType = LT.swt_sect).

[abodh]

Great that you found a fix! I have another one to report so will create a separate issue for that. Is there a scheduled release date?

On enums, I was just testing these actively in a terminal and hence the use of magic numbers. Although it’s useful to know that the integer property is faster. Thanks for the heads up and will be using the integer property moving forward.