list.extend and list comprehension

Question

When I need to add several identical items to the list I use list.extend:

a = [\'a\', \'b\', \'c\']
a.extend([\'d\']*3)

Result

Answer 1

import operator
a = [['a',2], ['b',2], ['c',1]]
nums = [[x[0]]*x[1] for x in a]
nums = reduce(operator.add, nums)