Python Program to Create a Lap Timer

When it is required to create a lap timer using Python, the time module is used. The program tracks individual lap times and cumulative time using keyboard interrupts to control the timer flow.

A lap timer records the duration of each lap in a sequence, commonly used in sports timing or performance tracking applications.

Example

import time

start_time = time.time()
end_time = start_time
lap_num = 1

print("Click on ENTER to count laps.\nPress CTRL+C to stop")

try:
    while True:
        input()
        time_laps = round((time.time() - end_time), 2)
        tot_time = round((time.time() - start_time), 2)
        
        print("Lap No. " + str(lap_num))
        print("Total Time: " + str(tot_time))
        print("Lap Time: " + str(time_laps))
        print("*" * 20)
        
        end_time = time.time()
        lap_num += 1

except KeyboardInterrupt:
    print("Exit!")

Output

Click on ENTER to count laps.
Press CTRL+C to stop

Lap No. 1
Total Time: 1.77
Lap Time: 1.77
********************

Lap No. 2
Total Time: 3.52
Lap Time: 1.75
********************
Exit!

How It Works

The program uses three key time measurements ?

• start_time ? Records when the timer begins

• end_time ? Updates after each lap to calculate individual lap duration

• current time ? Retrieved using time.time() for calculations

Key Components

The lap timer consists of several important elements ?

• Interactive Input ? input() waits for user to press Enter

• Time Calculation ? Lap time = current time - previous lap end time

• Total Time ? Cumulative time = current time - start time

• Exception Handling ? KeyboardInterrupt catches Ctrl+C to exit gracefully

Enhanced Version

import time

def lap_timer():
    start_time = time.time()
    end_time = start_time
    lap_num = 1
    lap_times = []
    
    print("=== LAP TIMER ===")
    print("Press ENTER to record each lap")
    print("Press CTRL+C to stop and show summary\n")
    
    try:
        while True:
            input(f"Press ENTER for Lap {lap_num}: ")
            
            current_time = time.time()
            lap_time = round(current_time - end_time, 2)
            total_time = round(current_time - start_time, 2)
            
            lap_times.append(lap_time)
            
            print(f"Lap {lap_num}: {lap_time}s (Total: {total_time}s)")
            print("-" * 30)
            
            end_time = current_time
            lap_num += 1
            
    except KeyboardInterrupt:
        print(f"\n=== TIMER STOPPED ===")
        print(f"Total Laps: {len(lap_times)}")
        if lap_times:
            print(f"Fastest Lap: {min(lap_times)}s")
            print(f"Average Lap: {round(sum(lap_times)/len(lap_times), 2)}s")

# Run the timer
lap_timer()

=== LAP TIMER ===
Press ENTER to record each lap
Press CTRL+C to stop and show summary

Press ENTER for Lap 1: 
Lap 1: 2.15s (Total: 2.15s)
------------------------------
Press ENTER for Lap 2: 
Lap 2: 1.89s (Total: 4.04s)
------------------------------

=== TIMER STOPPED ===
Total Laps: 2
Fastest Lap: 1.89s
Average Lap: 2.02s

Conclusion

The lap timer uses time.time() to measure intervals and KeyboardInterrupt for graceful termination. This creates an interactive timing system perfect for tracking performance across multiple laps or iterations.