How To Catch a Keyboardinterrupt in Python

Last Updated : 1 Jul, 2026

A KeyboardInterrupt exception occurs when a user manually interrupts the execution of a Python program, usually by pressing Ctrl + C (or Ctrl + Break on some systems). Python raises this exception to stop the currently running program.

Python 
while True:
    print("Program is running...")

Output

Program is running...
Program is running...
Program is running...

KeyboardInterrupt

Explanation: loop runs indefinitely. When the user presses Ctrl+C, Python interrupts the program and raises a KeyboardInterrupt exception.

This exception is commonly encountered in programs that run continuously, wait for user input, or perform long-running tasks. Handling KeyboardInterrupt allows a program to exit gracefully instead of terminating abruptly.

Common Causes

1. Interrupting an Infinite Loop: A KeyboardInterrupt often occurs when a program is stuck in an endless loop and the user wants to stop it.

Python 
while True:
    print("Running...")

Output

Running...
Running...
Running...

KeyboardInterrupt

Explanation: loop never ends on its own. Pressing Ctrl+C sends an interrupt signal to Python, causing a KeyboardInterrupt exception.

2. Interrupting User Input: The exception can also occur while a program is waiting for input.

Python 
name = input("Enter your name: ")
print(name)

Output

Enter your name:
KeyboardInterrupt

Explanation: program is waiting for user input. Instead of entering a value, pressing Ctrl+C interrupts the operation and raises KeyboardInterrupt.

Handling KeyboardInterrupt

1. try-except Block: most common way to handle KeyboardInterrupt is by using a try-except block.

Python 
try:
    while True:
        user_input = input("Enter something (Ctrl+C to exit): ")
        print("You entered:", user_input)

except KeyboardInterrupt:
    print("\nProgram terminated by user.")

Output

Enter something (Ctrl+C to exit): Python
You entered: Python

Enter something (Ctrl+C to exit):
Program terminated by user.

Explanation: When the user presses Ctrl+C, the KeyboardInterrupt exception is caught by the except block, allowing the program to exit gracefully.

2. Handling KeyboardInterrupt in Long-Running Processes: For long-running programs, it is often useful to perform cleanup operations before exiting.

Python 
import time

try:
    print("Processing... Press Ctrl+C to stop.")

    for i in range(10):
        time.sleep(1)
        print(f"Step {i + 1}")

except KeyboardInterrupt:
    print("\nProcess interrupted by user.")

finally:
    print("Exiting program.")

Output

Processing... Press Ctrl+C to stop.
Step 1
Step 2
Step 3

Process interrupted by user.
Exiting program.

Explanation: If the user interrupts the process, the except block handles the exception. The finally block executes regardless of whether an exception occurs, making it a good place for cleanup tasks.

3. Saving Data Before Exiting: In some applications, you may want to save progress before terminating.

Python 
try:
    while True:
        print("Collecting data...")

except KeyboardInterrupt:
    print("\nSaving progress before exit...")

Output

Collecting data...
Collecting data...

Saving progress before exit...

Explanation: When the user interrupts the program, the exception is caught and the program can perform important actions such as saving files, closing connections or storing progress.

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