Glyphs.clearLog() # clears macro window log
thisFont = Glyphs.font # frontmost font
listOfSelectedLayers = [ l for l in thisFont.selectedLayers if hasattr(l.parent, 'name')]
for thisLayer in listOfSelectedLayers:
thisGlyph.setLeftMetricsKey_("H")
print thisGlyph.leftMetricsKey
Returns H as the left metrics key but nothing changes in the UI or data…?