Fix: "" is not "null()" (sqlalchemy) or "None" (python)
Fix: "" is not "null()" (sqlalchemy) or "None" (python)

Meisterschueler/ogn-python,glidernet/ogn-python,kerel-fs/ogn-python,glidernet/ogn-python,Meisterschueler/ogn-python,glidernet/ogn-python,glidernet/ogn-python,Meisterschueler/ogn-python,Meisterschueler/ogn-python