from collections import defaultdict
rowdata = [['100004100', 'ABC1234AS', '45.96'], ['100004101', 'ABC1234AS', '104.95'], ['100004103','453SDFAS', '24.52']]
bucket = defaultdict(list)
for col1, col2, col3 in rowdata:
bucket[col2].append((col1,col3))
duplicates = {key:value for key, value in bucket.items() if len(value) > 1}
print (duplicates)
ZnJvbSBjb2xsZWN0aW9ucyBpbXBvcnQgZGVmYXVsdGRpY3QKCnJvd2RhdGEgPSBbWycxMDAwMDQxMDAnLCAnQUJDMTIzNEFTJywgJzQ1Ljk2J10sIFsnMTAwMDA0MTAxJywgJ0FCQzEyMzRBUycsICcxMDQuOTUnXSwgWycxMDAwMDQxMDMnLCc0NTNTREZBUycsICcyNC41MiddXQoKYnVja2V0ID0gZGVmYXVsdGRpY3QobGlzdCkKZm9yIGNvbDEsIGNvbDIsIGNvbDMgaW4gcm93ZGF0YToKCWJ1Y2tldFtjb2wyXS5hcHBlbmQoKGNvbDEsY29sMykpCgpkdXBsaWNhdGVzID0ge2tleTp2YWx1ZSBmb3Iga2V5LCB2YWx1ZSBpbiBidWNrZXQuaXRlbXMoKSBpZiBsZW4odmFsdWUpID4gMX0KCnByaW50IChkdXBsaWNhdGVzKQ==