timer.py

class Timer:
    def __init__(self, precision=1):
        self.precision = precision
        self.creation_time = time.time()
        self.start()
        
    def start(self):
        self.btime = time.time()
        
    @property
    def time(self) -> float:
        return round(time.time() - self.btime, self.precision)
    
    @property
    def time_total(self) -> float:
        return round(time.time() - self.creation_time, self.precision)
    
    def round(self) -> float:
        t = self.time
        self.start()
        return t

# usage
import time
timer = Timer(precision=3)
print(timer.time)
time.sleep(0.1)
print(timer.round())
time.sleep(0.1)
print(timer.round())
print(timer.time_total)