How to use Application.CalculationInterruptKey in the xlwings API way

The Application.CalculationInterruptKey property in Excel is a member that allows developers to control which key can be used to interrupt a long calculation in Excel. This is particularly useful when running complex or lengthy calculations where you might want to provide a way to stop the process without forcing Excel to become unresponsive. In xlwings, this property can be accessed and modified through the Application object, providing a programmatic way to manage calculation interruptions in automated Excel tasks.

Functionality:
The CalculationInterruptKey property determines the key that, when pressed during a calculation, will interrupt the process. It helps in creating more user-friendly or controlled environments by specifying whether interruptions are allowed and which key triggers them. This can prevent accidental interruptions or allow for deliberate stops in scenarios like data processing macros.

Syntax in xlwings:
In xlwings, you can access this property using the api property of the App or Book objects to reach the underlying Excel Application object. The syntax is as follows:

app = xw.apps.active # Get the active Excel application
interrupt_key = app.api.CalculationInterruptKey

To set the property, assign a value from the XlCalculationInterruptKey enumeration. The available options are:

• xlAnyKey (1): Any key press will interrupt the calculation.
• xlEscKey (2): Only the Esc key will interrupt the calculation.
• xlNoKey (3): No key will interrupt the calculation; this disables interruptions.

Parameters and Values:
The property accepts integer values corresponding to the enumeration. In xlwings, you can use the constants directly if imported, but typically, you can use the integer values for simplicity. For example:

• Use 1 for xlAnyKey.
• Use 2 for xlEscKey.
• Use 3 for xlNoKey.

Example Usage:
Here is a code example demonstrating how to set and retrieve the CalculationInterruptKey property using xlwings:

import xlwings as xw

# Connect to the active Excel application
app = xw.apps.active

# Get the current interrupt key setting
current_key = app.api.CalculationInterruptKey
print(f"Current interrupt key setting: {current_key}") # Output might be 2 for xlEscKey

# Set the interrupt key to xlAnyKey (any key press interrupts)
app.api.CalculationInterruptKey = 1 # Equivalent to xlAnyKey
print("Interrupt key set to xlAnyKey.")

# Perform a long calculation (e.g., a loop that simulates work)
# In a real scenario, this could be a heavy Excel calculation.
try:
    # Simulate a calculation that might be interrupted
    for i in range(1000000):
        # Some calculation code here
        if i % 100000 == 0:
            print(f"Processing... {i}")
except KeyboardInterrupt:
    print("Calculation was interrupted by user.")

# Reset to xlEscKey for standard behavior
app.api.CalculationInterruptKey = 2
print("Interrupt key reset to xlEscKey.")