a = [('when', 3), ('why', 4), ('throw', 9), ('send', 15), ('you', 1)]
b = ['the', 'when', 'send', 'we', 'us']
c=[]
for x in a:
if x[0] not in b:
c.append(x)
print c
YSA9IFsoJ3doZW4nLCAzKSwgKCd3aHknLCA0KSwgKCd0aHJvdycsIDkpLCAoJ3NlbmQnLCAxNSksICgneW91JywgMSldCiAKYiA9IFsndGhlJywgJ3doZW4nLCAnc2VuZCcsICd3ZScsICd1cyddCiAKYz1bXQogCmZvciB4IGluIGE6CiAgICBpZiB4WzBdIG5vdCBpbiBiOgogICAgICAgIGMuYXBwZW5kKHgpCiAgICAKcHJpbnQgYwo=