Programmatically stop execution of python script?

Stop script the standard way with sys.exit()

Graceful exit with sys.exit()

For normal termination, use sys.exit(). This is handy after completing all procedures, or running into a fatal error. You can supply exit codes optionally to show script's success (0) or failure (non-zero):

import sys

# Mission accomplished, time for martini 🍸
sys.exit(0)

# Houston, we have a problem!
sys.exit(1)
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Raising the white flag with SystemExit

You can also politely ask the script to halt by raising the SystemExit exception using raise SystemExit(0):

# I quit!
raise SystemExit(0)
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Going commando with exit() and quit()

Beyond sys.exit(), exit() and quit() are built-ins designed for interactive use, yet you can utilize these in scripts too. Yet, they're less desirable in production-grade code:

# Just walking out.. like a boss 😎
exit()
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Going out with a bang with non-zero exits

You can make a Python script go kaput by passing a non-zero argument indicating the error to sys.exit() when it hits a roadblock:

import sys

# Execute order 66! (Star Wars anyone?)
sys.exit('Error message')  
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Handling exceptions like a pro

Don't catch SystemExit unless you mean it

Avoid catching the SystemExit exception unless specifically intending to handle it, like logging or cleanup. An accidental catch may prevent the script from exiting:

try:
    # I must go, my people need me 🛸
    sys.exit()
except SystemExit:
    # Gotcha!
    print("Caught SystemExit") 
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Mastering exception handling

Use try/except blocks diligently. Catch just the exceptions that you're equipped to handle, allowing SystemExit and KeyboardInterrupt to pass through:

try:
    # Trying to divide by zero, are we? Bold move! 😅 
except Exception as e:
    # Oops! Cue facepalm 🤦
finally:
    # Phew, got through that! 🧹
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Exit strategies for diverse scenarios

Abrupt exit with os._exit()

When cleanup isn't required or poses risk, os._exit() can help you bolt immediately. It's the perfect escape pod for quick termination:

import os

os._exit(0)  # Seeya, wouldn't want to... you know the drill! 🏃‍♂️💨
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Stopping long processes with signals

Use signal handling with Python's signal module, ideal for long-running processes that need external prompts to quit:

import signal
import sys

def graceful_exit(signum, frame):
    sys.exit(0)

# Here comes the boom! 💣💥
signal.signal(signal.SIGTERM, graceful_exit)
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Time-bound script termination

Use sched or threading.Timer for timer-based termination:

import threading
import sys

def stop_script():
    sys.exit(0)

# Cuckoo! Time's up ⏰
timer = threading.Timer(10, stop_script)
timer.start()
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