yourlists = [
['4-7', '2-5', '2-9', '2-32', '2-16', '2-29', '2-13', '2-26', '2-20', '2-23'],
['2-32', '2-31', '2-36', '2-28', '2-34', '2-43', '2-41', '2-39']
]
result = [yourlist for yourlist in yourlists
if any(node.startswith('4-') for node in yourlist)]
print result
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[['4-7', '2-5', '2-9', '2-32', '2-16', '2-29', '2-13', '2-26', '2-20', '2-23']]