How to Mock Service Call Timeouts in Python

import time
from unittest.mock import Mock, patch

# Simulate a service call with configurable timeout
def call_service(service_name, timeout=5):
    """Mock a service call that may time out."""
    start = time.time()
    print(f"Calling {service_name}...")
    
    # Simulate service latency (randomized for realism)
    import random
    simulated_latency = random.uniform(0.1, 10)
    
    if simulated_latency > timeout:
        print(f"{service_name} timed out after {timeout}s (simulated latency was {simulated_latency:.1f}s)")
        raise TimeoutError(f"{service_name} exceeded timeout of {timeout}s")
    
    time.sleep(simulated_latency)
    print(f"{service_name} responded in {simulated_latency:.1f}s (within timeout)")
    return {"status": "ok", "service": service_name}

if __name__ == "__main__":
    # Use mock to prevent actual sleeping during test
    with patch("time.sleep", return_value=None), \
         patch("random.uniform", return_value=0.5) as mock_random:
        
        # Test successful call within timeout
        result = call_service("payment-service", timeout=2)
        print(f"Result: {result}")
        
        # Change simulated latency to exceed timeout
        mock_random.return_value = 5.0
        
        # Test timeout
        try:
            call_service("shipping-service", timeout=2)
        except TimeoutError as e:
            print(f"Caught: {e}")