m2o field contains only id of a record in other model (2one) so... 

when you print o.project_service the result on report will be as you already got... if you want to display just name you should consider writing something like: 

o.project_service.name    ... or o.projet_service.code... or maybe even: 

[[o.project_service.code]] - [[o.project_service.name]]  to get : code - name printed out...

hope it helps

EDIT 1. after additional question:yout method could be written better/faster like this:.

cr.execute("select id, int_service, ext_service, unit_service, int_service_unit, ext_service_unit, service_type, service_id from project_services")

ret=cr.dictfetchall()

retunr ret

this 2 lines will do the same as your code starting with:

obj = self.pool.get('project_service')  ...

return ret

This part you should check: 

obj_ids = obj.search(cr, uid, [], context=context)

if you need only project_service related to selected project_id , then this line should be like:

obj_ids = obj.search(cr, uid, [('project_id','=',project_id)])

(or use:

cr.execute("select id, project_id, int_service, ext_service, unit_service, int_service_unit, ext_service_unit, service_type, service_id from project_services where project_id = %(project_id)s", {'project_id' : project_id})

or 

cr.execute("select id, project_id, int_service, ext_service, unit_service, int_service_unit, ext_service_unit, service_type, service_id from project_services where project_id = %s" % project_id)

both synthax will work )

test this out, see if it will work...

Here is my function. It works very well.

Ist it Fine to make like that in project_services.Which one is correct??????????

def get_inputs(self, cr, uid,ids, state, project, context=None):

ret = []

print ('--------------------get_inputs---------------------')

project_id = _get_project_id_by_name (self,cr, uid, project, context)

print ('project =')

print project_id

obj = self.pool.get('project_service')

obj_ids = obj.search(cr, uid, [], context=context)

res = obj.read(cr, uid, obj_ids, ['id', 'int_service','ext_service','unit_service','int_service_unit','ext_service_unit','service_type','service_id'], context)

print res

for r in res :

inputs = {

'project_services': r['id'] or id,

'project_id' : project_id,

'int_services': r['int_service'],

'ext_services': r['ext_service'],

'unit_services': r['unit_service'],

'int_services_unit': r['int_service_unit'],

'ext_services_unit': r['ext_service_unit'],

'service_type': r['service_type'],

'service_idd': r['service_id'],

}

ret += [inputs]

print ('------------liste de services-------')

print ret

return ret