Sequencing immunoglobulin using high-throughput sequencing platform (Ig-Seq) enables to snapshot the adaptive immune repertoires, giving us the insights to better understanding immune responses in health and disease. Large amounts of raw data produced by Ig-Seq require effective ways for anlaysis. PyDAIR is a tool that aims to identify V, D, J and CDR3 segments, and detects insertions and deletions on V-D and D-J junctions.