time_monitor.py

from time import perf_counter

class TimeMonitor:
    def __enter__(self):
        self.report_times = [perf_counter()]
        self.report_tags = ["Start"]

        return self

    def tick(self, tag):
        self.report_times.append(perf_counter())
        self.report_tags.append(tag)

    def __exit__(self, *exc):
        self.report_times.append(perf_counter())
        self.report_tags.append("Finish")

        for i in range(len(self.report_tags) - 1):
            elapsed = self.report_times[i + 1] - self.report_times[i]
            tag = f"{self.report_tags[i]} - {self.report_tags[i + 1]}"

            print(f"{elapsed:12.6f} - {tag}")