Replace data sources of layers in a map document using two different methods.

replaceLayerSources.py

#
# @date 25/03/2015
# @author Cindy Williams
#
# Replace data sources of layers in a mxd using
# two different methods.
#
# For use in the Python window in ArcMap.
#

mxd = arcpy.mapping.MapDocument("CURRENT")
sde_old = r"C:\Database Connections\old.sde"
sde_new = r"C:\Database Connections\new.sde"

mxd.findAndReplaceWorkspacePaths(old, new)

# If the above does not work because ArcMap is being ArcMap

lyrs = arcpy.mapping.ListLayers(mxd)
for lyr in lyrs:
    lyr.replaceDataSource(new, "SDE_WORKSPACE", lyr.datasetName)

arcpy.RefreshTOC()