In cases where performance is your top priority and you only need to work with SNMP v1 and v2c systems and you do not mind writing much more code, then there is a low-level API to SNMP v1/v2c PDU and PySNMP I/O engine. There's practically no SNMP engine or SMI infrastructure involved in the operations of these almost wire-level interfaces. Although MIB services can still be used separately.
A packet-level API-based application typically manages both SNMP message building/parsing and network communication via one or more transports. It's fully up to the application to handle failures on message and transport levels.
SNMPv1/v2c Manager-side operations:
SNMPv1/v2c Agent-side operations:
For more details on PySNMP programming model and interfaces, please refer to the documentation.