### Basic Circuit Breaker Usage

Source: https://github.com/fabfuel/circuitbreaker/blob/develop/README.rst

Decorate a function with @circuit for basic circuit breaker functionality with default settings. This monitors failures, resets on success, opens after 5 failures, and attempts a test execution after 30 seconds.

```python
from circuitbreaker import circuit

@circuit
def external_call():
    ...
```

--------------------------------

### Configuring Failure Threshold and Expected Exception

Source: https://github.com/fabfuel/circuitbreaker/blob/develop/README.rst

Customize the circuit breaker by setting a custom failure threshold and specifying the exact exception types that should trigger a failure. This helps in protecting against cascading failures by only reacting to integration-specific errors.

```python
from circuitbreaker import circuit

@circuit(failure_threshold=10, expected_exception=ConnectionError)
def external_call():
    ...
```

--------------------------------

### Apply Custom Circuit Breaker as Object

Source: https://github.com/fabfuel/circuitbreaker/blob/develop/README.rst

Use an instance of a custom circuit breaker class as a decorator for a function.

```python
@MyCircuitBreaker()
def external_call():
    ...
```

--------------------------------

### Apply Custom Circuit Breaker via Decorator Proxy

Source: https://github.com/fabfuel/circuitbreaker/blob/develop/README.rst

Apply a custom circuit breaker class to a function using the 'circuit' decorator with the 'cls' parameter.

```python
@circuit(cls=MyCircuitBreaker)
def external_call():
    ...
```

--------------------------------

### Custom Circuit Breaker Subclass

Source: https://github.com/fabfuel/circuitbreaker/blob/develop/README.rst

Extend the CircuitBreaker class to define custom failure thresholds, recovery timeouts, and expected exceptions.

```python
from circuitbreaker import CircuitBreaker

class MyCircuitBreaker(CircuitBreaker):
    FAILURE_THRESHOLD = 10
    RECOVERY_TIMEOUT = 60
    EXPECTED_EXCEPTION = RequestException
```

--------------------------------

### Custom Failure Logic with Callable

Source: https://github.com/fabfuel/circuitbreaker/blob/develop/README.rst

Use a callable function to define complex logic for identifying failures. This allows for fine-grained control over which exceptions trigger the circuit breaker, such as distinguishing between general request errors and specific HTTP status codes.

```python
# Assume we are using the requests library
def is_not_http_error(thrown_type, thrown_value):
    return issubclass(thrown_type, RequestException) and not issubclass(thrown_type, HTTPError)

def is_rate_limited(thrown_type, thrown_value):
    return issubclass(thrown_type, HTTPError) and thrown_value.status_code == 429

@circuit(expected_exception=is_not_http_error)
def call_flaky_api(...):
    rsp = requests.get(...)
    rsp.raise_for_status()
    return rsp

@circuit(expected_exception=is_rate_limited)
def call_slow_server(...):
    rsp = requests.get(...)
    rsp.raise_for_status()
    return rsp
        
```

--------------------------------

### Async Function Circuit Breaker

Source: https://github.com/fabfuel/circuitbreaker/blob/develop/README.rst

Supports asynchronous functions by decorating them with @circuit. The behavior and default settings remain the same as for synchronous functions.

```python
@circuit
async def external_call():
    ...
```

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