a = [('misure', 'di', 'protezione'), ('libertà ', 'di', 'espressione'), ('misure', 'di', 'protezione', 'libertà ', 'di', 'espressione')]
try:
b = [tuple(j for j in i if 'di' not in j) for i in a]
print b
except Exception as e:
print e
YSA9IFsoJ21pc3VyZScsICdkaScsICdwcm90ZXppb25lJyksICgnbGliZXJ0w6AnLCAnZGknLCAnZXNwcmVzc2lvbmUnKSwgKCdtaXN1cmUnLCAnZGknLCAncHJvdGV6aW9uZScsICdsaWJlcnTDoCcsICdkaScsICdlc3ByZXNzaW9uZScpXQoKdHJ5OgoJYiA9IFt0dXBsZShqIGZvciBqIGluIGkgaWYgJ2RpJyBub3QgaW4gaikgZm9yIGkgaW4gYV0KCXByaW50IGIKZXhjZXB0IEV4Y2VwdGlvbiBhcyBlOgoJcHJpbnQgZQ==
[('misure', 'protezione'), ('libert\xc3\xa0', 'espressione'), ('misure', 'protezione', 'libert\xc3\xa0', 'espressione')]