docs/user_guide/inspection.md

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(inspection)=
# {fas}`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)

:::{dropdown} Examples
:animate: fade-in-slide-down
:color: primary
:icon: file-code

```python
>>> from requests_cache import CachedSession
>>> session = CachedSession(expire_after=timedelta(days=1))

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

>>> # These attributes will be populated for cached responses
>>> response = session.get('https://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

### Checking for responses
Use {py:meth}`.BaseCache.contains` to check if a given request is cached.

Check if a specific URL is cached:
```python
>>> print(session.cache.contains(url='https://httpbin.org/get'))
```

To match additional request values (parameters, headers, etc), you can pass a
{py:class}`~requests.models.Request` object instead:
```python
>>> from requests import Request

>>> request = Request('GET', 'https://httpbin.org/get', params={'k': 'v'})
>>> print(session.cache.contains(request=request))
```

You can also check for a specific cache key:
```python
>>> print(session.cache.contains('d1e666e9fdfb3f86'))
```

### Filtering responses
Use {py:meth}`.BaseCache.filter` to get responses with optional filters. By default, it returns all
responses except any invalid ones that would raise an exception:
```python
>>> for response in session.cache.filter():
>>>     print(response)
```

Get unexpired responses:
```python
>>> for response in session.cache.filter(expired=False):
>>>     print(response)
```

Get keys for **only** expired responses:
```python
>>> expired_responses = session.cache.filter(valid=False, expired=True)
>>> keys = [response.cache_key for response in expired_responses]
```

### Deleting responses
Use {py:meth}`.BaseCache.delete` to manually delete responses. See {ref}`manual_removal` for
examples.

### Response URLs
You can use {py:meth}`.BaseCache.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']
```

### Other response details
If needed, you can access all responses via `CachedSession.cache.responses`, which is a dict-like
interface to the cache backend, where:
* Keys are cache keys (a hash of matched request information)
* Values are {py:class}`.CachedResponse` objects

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