AttributeError: 'tuple' object has no attribute 'join'

[TalHuang]

Why this code return error
AttributeError: 'tuple' object has no attribute 'join'

Any help will be appreciated;

Thanks

import string

template_text = '''
    Delimiter : %%
    Replaced  : %with_underscore
    Ignored   : %notunderscored
'''


d = { 'with_underscore' : 'replaced',
      'notunderscored'  : 'not replaced'    
    }

class MyTemplate(string.Template):
    delimiter = '%',
    idpattern = '[a-z]+_[a-z]+'
    
t = MyTemplate(template_text)
print 'Modified ID pattern:'
print t.safe_substitute(d);

[bvdet]

Get rid of the comma after

    delimiter = '%',

[TalHuang]

ok, I am too careless, Thanks