node_list = cmds.ls()

print(node_list)
# Result: 9044


start = datetime.datetime.now()
for i in xrange(100):
    shading_engine = cmds.ls(type='shadingEngine')
    if not shading_engine:
        continue
    found = False
    for node in node_list:
        if node in shading_engine:
            found = True
            break
    if found:
        pass
print(datetime.datetime.now() - start)
# Result: 0:00:00.082000


start = datetime.datetime.now()
for i in xrange(100):
    shading_engine = cmds.ls(type='shadingEngine')
    if not shading_engine:
        continue
    found = False
    for sg in shading_engine:
        if sg in node_list:
            found = True
            break
    if found:
        pass
print(datetime.datetime.now() - start)
# Result: 0:00:00.101000


start = datetime.datetime.now()
for i in xrange(100):
    shading_engine = cmds.ls(type='shadingEngine')
    if not shading_engine:
        continue
    shading_engine_set = set(shading_engine)
    node_set = set(node_list)
    if shading_engine_set & node_set:
        pass
    else:
        pass
print(datetime.datetime.now() - start)
# Result: 0:00:00.129000


from maya import cmds
import datetime
start = datetime.datetime.now()
for i in xrange(100):
    node_types = [cmds.nodeType(l) for l in node_list]
    if 'shadingEngine' in node_types:
        pass
    else:
        pass
print(datetime.datetime.now() - start)
# Result: 0:00:07.147000


start = datetime.datetime.now()
for i in xrange(100):
    node_types = {cmds.nodeType(l):True for l in node_list}
    if 'shadingEngine' in node_types:
        pass
    else:
        pass
print(datetime.datetime.now() - start)
# Result: 0:00:07.086000


start = datetime.datetime.now()
for i in xrange(100):
    if cmds.ls(node_list, type='shadingEngine'):
        pass
    else:
        pass
print(datetime.datetime.now() - start)
# Result: 0:00:04.859000