docs/user_guide/inspection.md

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(inspection)=
# {fa}`search` Cache Inspection
Here are some ways to get additional information out of the cache session, backend, and responses:

## Response Details
The following attributes are available on responses:
- `from_cache`: indicates if the response came from the cache
- `cache_key`: The unique identifier used to match the request to the response (see {ref}`matching`
  for details)
- `created_at`: {py:class}`~datetime.datetime` of when the cached response was created or last updated
- `expires`: {py:class}`~datetime.datetime` after which the cached response will expire (see
  {ref}`expiration` for details)
- `is_expired`: indicates if the cached response is expired (if, for example, an old response was returned due to a request error)

Examples:
:::{admonition} Example code
:class: toggle
```python
>>> from requests_cache import CachedSession
>>> session = CachedSession(expire_after=timedelta(days=1))

>>> # Placeholders are added for non-cached responses
>>> response = session.get('http://httpbin.org/get')
>>> print(response.from_cache, response.created_at, response.expires, response.is_expired)
False None None None

>>> # Values will be populated for cached responses
>>> response = session.get('http://httpbin.org/get')
>>> print(response.from_cache, response.created_at, response.expires, response.is_expired)
True 2021-01-01 18:00:00 2021-01-02 18:00:00 False

>>> # Print a response object to get general information about it
>>> print(response)
'request: GET https://httpbin.org/get, response: 200 (308 bytes), created: 2021-01-01 22:45:00 IST, expires: 2021-01-02 18:45:00 IST (fresh)'
```
:::

## Cache Contents
You can use `CachedSession.cache.urls` to see all URLs currently in the cache:
```python
>>> session = CachedSession()
>>> print(session.cache.urls)
['https://httpbin.org/get', 'https://httpbin.org/stream/100']
```

If needed, you can get more details on cached responses via `CachedSession.cache.responses`, which
is a dict-like interface to the cache backend. See {py:class}`.CachedResponse` for a full list of
attributes available.

For example, if you wanted to to see all URLs requested with a specific method:
```python
>>> post_urls = [
...     response.url for response in session.cache.responses.values()
...     if response.request.method == 'POST'
... ]
```

You can also inspect `CachedSession.cache.redirects`, which maps redirect URLs to keys of the
responses they redirect to.

Additional `keys()` and `values()` wrapper methods are available on {py:class}`.BaseCache` to get
combined keys and responses.
```python
>>> print('All responses:')
>>> for response in session.cache.values():
>>>     print(response)

>>> print('All cache keys for redirects and responses combined:')
>>> print(list(session.cache.keys()))
```

Both methods also take a `check_expiry` argument to exclude expired responses:
```python
>>> print('All unexpired responses:')
>>> for response in session.cache.values(check_expiry=True):
>>>     print(response)
```

Similarly, you can get a count of responses with {py:meth}`.BaseCache.response_count`, and optionally
exclude expired responses:
```python
>>> print(f'Total responses: {session.cache.response_count()}')
>>> print(f'Unexpired responses: {session.cache.response_count(check_expiry=True)}')
```