The nature of write concern management is quite different from that of establishing read preferences. The difference is that all replica set members are ultimately involved in a write operation. When the database is modified, the changes need to be synchronized by the entire replica set. More importantly, what is at stake in a write operation is how many (if any) acknowledgments must be received before the write operation is considered a success (https://docs.mongodb.com/manual/reference/write-concern/#acknowledgment-behavior).
As with read preferences, write concerns are expressed in the form of keyword arguments when defining a pymongo.mongo_client.MongoClient instance. The following list summarizes the applicable **kwargs parameters:
- w=<int>|<string>: Values can be either an integer or a string. If you set a value of 0, write acknowledgment is disabled. This increases the speed of write operations but...
