Generating tracing data
It's finally time to start generating telemetry from the application! There are several ways to create a span in OpenTelemetry; the first one we'll use is to call start_span on the tracer instance we obtained previously. This will create a span object, using the only required string argument as the name of the span. The span object is the building block of distributed tracing and is intended to represent a unique unit of work in our application. In the following example, we will create a new Span object before calling a method that will do some work. Since our application is a shopper, the first thing the shopper will do is browse the store. In order for the tracing data to be useful, it's important to use a meaningful name in the creation of the span. Once browse has returned, we will call end on the span object to signal that the work is complete:
shopper.py
def browse():
print("visiting the grocery store"...