The data was captured from LTE network.

I don't know how to recognize count TCP retransmission of a single TCP flow, using
Python. 
Could I recognize the type of retransmission? It's because of congestion or packet loss?

Thanks.
I did it in C but the general ideas is, you need to keep track of TCP sequence numbers (there are two streams for each TCP session, one from client to server, the other is from server to client).  This is a little complex.
For each stream, you have a pointer to keep track of the consecutive sequence numbers sent so far and use a linked-list to keep track of the pairs ( sequence number + data length) that have a gap to the pointer. Each time you see a new data packet in the stream, you either update the pointer, or add to the linked-list. Note that after you update the pointer, you should check if the linked-list to see if some of the gaps are closed.  You can tell retransmitted data packets this way.
Hope it helps.  Good luck.
How could I find TCP retransmission and packet loss from pcap file?