Python & Maya : Namespaces

Another way to go about this would be to skip the dependency of string naming and adopt retrieving nodes via UUID instead. See cmds.ls in conjunction with the -uuid flag found here.

Namespace are really just string name prefixes appended onto an object's name. As long as the namespace exists, you can rename an object to add/remove it from a namespace. For instance:

import maya.cmds as cmds

loc = cmds.spaceLocator()
cmds.ls(loc)[0]  # Result: u'locator1' # 

cmds.namespace(add='foobar')  # Result: u'foobar' # 
loc = cmds.rename(loc, ':foobar:{}'.format(loc))  # Result: u'foobar:my_locator' #

cmds.rename(loc, ':my_locator')  # Result: u'my_locator' # 

The idea behind UUID is that nodes get tagged with a special string attribute which is unique to the node and does not change when the node is renamed. For example, notice the name changes while the UUID remains the same:

import maya.cmds as cmds

loc = cmds.spaceLocator()
cmds.ls(loc, uuid=True)[0]  # u'60446AC7-4398-E3CB-4C27-6BA417626E41' # 
cmds.ls(loc)[0]  # Result: u'locator1' # 


loc = cmds.rename(loc, 'my_locator')
cmds.ls(loc, uuid=True)[0]  # Result: u'60446AC7-4398-E3CB-4C27-6BA417626E41' #
cmds.ls(loc)[0]  # Result: u'my_locator' # 

Armed with this info, we now know that a node will always have the same, unchanging UUID for the entirety of its lifespan, regardless of what namespace it is moved (via naming) to/from.

Putting this all together, here is how we use the ls command in conjunction with uuid:

# Query the UUID of our locator
cmds.ls(loc, uuid=True)[0]  # Result: u'60446AC7-4398-E3CB-4C27-6BA417626E41' #

# Retrieve the locator name string via UUID
cmds.ls(u'60446AC7-4398-E3CB-4C27-6BA417626E41')[0]  # Result: u'my_locator' # 

You can use cmds.namespaceInfo

This command can list all available namespaces and its containting objects.

Read more about here: namespaceInfo

when im coding something like that i generally use an asterix for where the namespace is like so.

shldr = cmds.xform('*:L_shldrFK_match_LOC', ws = True, t = True, q = True)

it depends if your going to have other things in your scene under other namespace with the same name though because then it won't work

we need a list with all namespaces to find the correct one:

namespaces = cmds.namespaceInfo(lon=True)
current_namespace = cmds.namespaceInfo(currentNamespace=True)
references = cmds.ls(type="reference")

you can work with this information but ignore the namespace is not really good, because the main function of referencing is to have a environment/character/prop asset multiply times with the last update in you scene...so

shldr = cmds.xform('*:L_shldrFK_match_LOC', ws = True, t = True, q = True)

will work only if you have only one character in you scene.