#from within CMF management screen (/manage)

#click on portal_memberdata, click on properties
#add a string field called fullname

#click Find tab, type join_form, and click find
#add a field called fullname

#your done, at the root of the CMF you can create a Script (Python)
#called getAllMemberDataAsCSV, which will list in CSV form all members
#and their attributes

#prints out a CSV pf member and member properties
text = ''
memberProperties = context.portal_memberdata.propertyIds()
memberProperties.insert(0, 'id')

for p in memberProperties:
    #write out the first line
    text += p + ', '
    
text += '\n' #first line has been written

for member in context.portal_membership.listMembers():
    for p in memberProperties:
        if hasattr(member, p): text+=str(getattr(member,p))
        text+=', '
    text+='\n'

return text