Several ArcPy functions take strings as geodatabase identifiers. I've looked through the ESRI docs, but can't find a good reference for the various acceptable formats. I'm looking for examples of each of the different kinds of geodatabases (personal geodatabase, file geodatabase, remote geodatabase).
For example,
gdb = "C:/MyData/PersonalGeodatabase.mdb" # personal geodatabase
gdb = "C:/MyData/FileGeodatabase.gdb" # file geodatabase
gdb = "" # named instance SQL Server Express
gdb = "" # sde database in SQL Server
If possible I would prefer that there not be a corresponding entry in ArcCatalog to make this work. The current working examples I have seen here all seem to rely on specifically named connections in ArcCatalog.