# azure.core.pipeline.policies package

## Module contents

class `azure.core.pipeline.policies.``HTTPPolicy`

  Bases: `abc.ABC`, `typing.Generic`

  An HTTP policy ABC.

  Use with a synchronous pipeline.

  Parameters: | next (HTTPPolicy or HttpTransport) – Use to process the next policy in the pipeline. Set when pipeline is instantiated and all policies chained.

  `send`(request)

    Abstract send method for a synchronous pipeline. Mutates the request.

    Context content is dependent on the HttpTransport.

    Parameters: | request (PipelineRequest) – The pipeline request object
    Returns: | The pipeline response object.
    Return type: | PipelineResponse

class `azure.core.pipeline.policies.``SansIOHTTPPolicy`

  Bases: `typing.Generic`

  Represents a sans I/O policy.

  SansIOHTTPPolicy is a base class for policies that only modify or mutate a request based on the HTTP specification, and do no depend on the specifics of any particular transport. SansIOHTTPPolicy subclasses will function in either a Pipeline or an AsyncPipeline, and can act either before the request is done, or after. You can optionally make these methods coroutines (or return awaitable objects) but they will then be tied to AsyncPipeline usage.

  `on_exception`(request)

    Is executed if an exception is raised while executing the next policy.

    Developer can optionally implement this method to return True if the exception has been handled and should not be forwarded to the caller.

    This method is executed inside the exception handler.

    Parameters: | request (PipelineRequest) – The Pipeline request object
    Returns: | False by default, override with True to stop the exception.
    Return type: | bool

    Example:

  `on_request`(request)

    Is executed before sending the request from next policy.

    Parameters: | request (PipelineRequest) – Request to be modified before sent from next policy.

  `on_response`(request, response)

    Is executed after the request comes back from the policy.

    Parameters:

    - request (PipelineRequest) – Request to be modified after returning from the policy.
    - response (PipelineResponse) – Pipeline response object

class `azure.core.pipeline.policies.``BearerTokenCredentialPolicy`(credential, *scopes, **kwargs)

  Bases: `azure.core.pipeline.policies._authentication._BearerTokenCredentialPolicyBase`, `azure.core.pipeline.policies._base.SansIOHTTPPolicy`

  Adds a bearer token Authorization header to requests.

  Parameters:

  - credential (TokenCredential) – The credential.
  - scopes (str) – Lets you specify the type of access needed.

  Raises: | `ServiceRequestError`

  `on_request`(request)

    Adds a bearer token Authorization header to request and sends request to next policy.

    Parameters: | request (PipelineRequest) – The pipeline request object

class `azure.core.pipeline.policies.``HeadersPolicy`(base_headers=None, **kwargs)

  Bases: `azure.core.pipeline.policies._base.SansIOHTTPPolicy`

  A simple policy that sends the given headers with the request.

  This will overwrite any headers already defined in the request. Headers can be configured up front, where any custom headers will be applied to all outgoing operations, and additional headers can also be added dynamically per operation.

  Parameters: | base_headers (dict) – Headers to send with the request.

  Example:

  `add_header`(key, value)

    Add a header to the configuration to be applied to all requests.

    Parameters:

    - key (str) – The header.
    - value (str) – The header’s value.

  `on_request`(request)

    Updates with the given headers before sending the request to the next policy.

    Parameters: | request (PipelineRequest) – The PipelineRequest object

  `headers`

    The current headers collection.

class `azure.core.pipeline.policies.``UserAgentPolicy`(base_user_agent=None, **kwargs)

  Bases: `azure.core.pipeline.policies._base.SansIOHTTPPolicy`

  User-Agent Policy. Allows custom values to be added to the User-Agent header.

  Parameters: | base_user_agent (str) – Sets the base user agent value.
  Keyword Arguments:

  - user_agent_overwrite (bool) – Overwrites User-Agent when True. Defaults to False.
  - user_agent_use_env (bool) – Gets user-agent from environment. Defaults to True.
  - user_agent (str) – If specified, this will be added in front of the user agent string.
  - sdk_moniker (str) – If specified, the user agent string will be azsdk-python-[sdk_moniker] Python/[python_version] ([platform_version])

  Example:

  `add_user_agent`(value)

    Add value to current user agent with a space. :param str value: value to add to user agent.

  `on_request`(request)

    Modifies the User-Agent header before the request is sent.

    Parameters: | request (PipelineRequest) – The PipelineRequest object

  `user_agent`

    The current user agent value.

class `azure.core.pipeline.policies.``NetworkTraceLoggingPolicy`(logging_enable=False, **kwargs)

  Bases: `azure.core.pipeline.policies._base.SansIOHTTPPolicy`

  The logging policy in the pipeline is used to output HTTP network trace to the configured logger.

  This accepts both global configuration, and per-request level with “enable_http_logger”

  Parameters: | logging_enable (bool) – Use to enable per operation. Defaults to False.

  Example:

  `on_request`(request)

    Logs HTTP request to the DEBUG logger.

    Parameters: | request (PipelineRequest) – The PipelineRequest object.

  `on_response`(request, response)

    Logs HTTP response to the DEBUG logger.

    Parameters:

    - request (PipelineRequest) – The PipelineRequest object.
    - response (PipelineResponse) – The PipelineResponse object.

class `azure.core.pipeline.policies.``ContentDecodePolicy`

  Bases: `azure.core.pipeline.policies._base.SansIOHTTPPolicy`

  Policy for decoding unstreamed response content.

  classmethod `deserialize_from_http_generics`(response)

    Deserialize from HTTP response.

    Headers will tested for “content-type”

    Parameters: | response – The HTTP response
    Raises: | DecodeError – If deserialization fails
    Returns: | A dict or XML tree, depending of the mime-type

  classmethod `deserialize_from_text`(data, mime_type=None, response=None)

    Decode response data according to content-type.

    Accept a stream of data as well, but will be load at once in memory for now. If no content-type, will return the string version (not bytes, not stream)

    Parameters:

    - response (HttpResponse) – The HTTP response.
    - mime_type (str) – The mime type. As mime type, charset is not expected.
    - response – If passed, exception will be annotated with that response

    Raises: | DecodeError – If deserialization fails
    Returns: | A dict or XML tree, depending of the mime_type

  `on_response`(request, response)

    Extract data from the body of a REST response object. This will load the entire payload in memory. Will follow Content-Type to parse. We assume everything is UTF8 (BOM acceptable).

    Parameters:

    - request (PipelineRequest) – The PipelineRequest object.
    - response (PipelineResponse) – The PipelineResponse object.
    - raw_data – Data to be processed.
    - content_type – How to parse if raw_data is a string/bytes.

    Raises:

    - JSONDecodeError – If JSON is requested and parsing is impossible.
    - UnicodeDecodeError – If bytes is not UTF8
    - xml.etree.ElementTree.ParseError – If bytes is not valid XML
    - DecodeError – If deserialization fails

  `CONTEXT_NAME` = 'deserialized_data'
  `JSON_REGEXP` = re.compile('^(application|text)/([0-9a-z+.]+\\+)?json$')

class `azure.core.pipeline.policies.``RetryMode`

  Bases: `str`, `enum.Enum`

  An enumeration.

  `Exponential` = 'exponential'
  `Fixed` = 'fixed'

class `azure.core.pipeline.policies.``RetryPolicy`(**kwargs)

  Bases: `azure.core.pipeline.policies._base.HTTPPolicy`

  A retry policy.

  The retry policy in the pipeline can be configured directly, or tweaked on a per-call basis.

  Keyword Arguments:

  - retry_total (int) – Total number of retries to allow. Takes precedence over other counts. Default value is 10.
  - retry_connect (int) – How many connection-related errors to retry on. These are errors raised before the request is sent to the remote server, which we assume has not triggered the server to process the request. Default value is 3.
  - retry_read (int) – How many times to retry on read errors. These errors are raised after the request was sent to the server, so the request may have side-effects. Default value is 3.
  - retry_status (int) – How many times to retry on bad status codes. Default value is 3.
  - retry_backoff_factor (float) – A backoff factor to apply between attempts after the second try (most errors are resolved immediately by a second try without a delay). In fixed mode, retry policy will alwasy sleep for {backoff factor}. In ‘exponential’ mode, retry policy will sleep for: {backoff factor} * (2 ** ({number of total retries} - 1)) seconds. If the backoff_factor is 0.1, then the retry will sleep for [0.0s, 0.2s, 0.4s, …] between retries. The default value is 0.8.
  - retry_backoff_max (int) – The maximum back off time. Default value is 120 seconds (2 minutes).
  - retry_mode (RetryMode) – Fixed or exponential delay between attemps, default is exponential.

  Example:

  `configure_retries`(options)

    Configures the retry settings.

    Parameters: | options – keyword arguments from context.
    Returns: | A dict containing settings and history for retries.
    Return type: | dict

  `get_backoff_time`(settings)

    Returns the current backoff time.

    Parameters: | settings (dict) – The retry settings.
    Returns: | The current backoff value.
    Return type: | float

  `get_retry_after`(response)

    Get the value of Retry-After in seconds.

    Parameters: | response (PipelineResponse) – The PipelineResponse object
    Returns: | Value of Retry-After in seconds.
    Return type: | float

  `increment`(settings, response=None, error=None)

    Increment the retry counters.

    Parameters:

    - settings – The retry settings.
    - response (PipelineResponse) – A pipeline response object.
    - error – An error encountered during the request, or None if the response was received successfully.

    Returns: | Whether any retry attempt is available True if more retry attempts available, False otherwise
    Return type: | bool

  `is_exhausted`(settings)

    Checks if any retries left.

    Parameters: | settings (dict) – the retry settings
    Returns: | False if have more retries. True if retries exhausted.
    Return type: | bool

  `is_retry`(settings, response)

    Checks if method/status code is retryable.

    Based on whitelists and control variables such as the number of total retries to allow, whether to respect the Retry-After header, whether this header is present, and whether the returned status code is on the list of status codes to be retried upon on the presence of the aforementioned header.

    Parameters:

    - settings (dict) – The retry settings.
    - response (PipelineResponse) – The PipelineResponse object

    Returns: | True if method/status code is retryable. False if not retryable.
    Return type: | bool

  classmethod `no_retries`()

    Disable retries.

  `parse_retry_after`(retry_after)

    Helper to parse Retry-After and get value in seconds.

    Parameters: | retry_after (str) – Retry-After header
    Return type: | float

  `send`(request)

    Sends the PipelineRequest object to the next policy. Uses retry settings if necessary.

    Parameters: | request (PipelineRequest) – The PipelineRequest object
    Returns: | Returns the PipelineResponse or raises error if maximum retries exceeded.
    Return type: | PipelineResponse
    Raises: | ~azure.core.exceptions.AzureError if maximum retries exceeded.
    Raises: | ~azure.core.exceptions.ClientAuthenticationError if authentication

  `sleep`(settings, transport, response=None)

    Sleep between retry attempts.

    This method will respect a server’s `Retry-After` response header and sleep the duration of the time requested. If that is not present, it will use an exponential backoff. By default, the backoff factor is 0 and this method will return immediately.

    Parameters:

    - settings (dict) – The retry settings.
    - transport – The HTTP transport type.
    - response (PipelineResponse) – The PipelineResponse object.

  `update_context`(context, retry_settings)

    Updates retry history in pipeline context.

    Parameters:

    - context (PipelineContext) – The pipeline context.
    - retry_settings (dict) – The retry settings.

  `BACKOFF_MAX` = 120

    Maximum backoff time.

class `azure.core.pipeline.policies.``RedirectPolicy`(**kwargs)

  Bases: `azure.core.pipeline.policies._base.HTTPPolicy`

  A redirect policy.

  A redirect policy in the pipeline can be configured directly or per operation.

  Keyword Arguments:

  - permit_redirects (bool) – Whether the client allows redirects. Defaults to True.
  - redirect_max (int) – The maximum allowed redirects. Defaults to 30.

  Example:

  `configure_redirects`(options)

    Configures the redirect settings.

    Parameters: | options – Keyword arguments from context.
    Returns: | A dict containing redirect settings and a history of redirects.
    Return type: | dict

  `get_redirect_location`(response)

    Checks for redirect status code and gets redirect location.

    Parameters: | response (PipelineResponse) – The PipelineResponse object
    Returns: | Truthy redirect location string if we got a redirect status code and valid location. `None` if redirect status and no location. `False` if not a redirect status code.

  `increment`(settings, response, redirect_location)

    Increment the redirect attempts for this request.

    Parameters:

    - settings (dict) – The redirect settings
    - response (PipelineResponse) – A pipeline response object.
    - redirect_location (str) – The redirected endpoint.

    Returns: | Whether further redirect attempts are remaining. False if exhausted; True if more redirect attempts available.
    Return type: | bool

  classmethod `no_redirects`()

    Disable redirects.

  `send`(request)

    Sends the PipelineRequest object to the next policy. Uses redirect settings to send request to redirect endpoint if necessary.

    Parameters: | request (PipelineRequest) – The PipelineRequest object
    Returns: | Returns the PipelineResponse or raises error if maximum redirects exceeded.
    Return type: | PipelineResponse
    Raises: | ~azure.core.exceptions.TooManyRedirectsError if maximum redirects exceeded.

  `REDIRECT_HEADERS_BLACKLIST` = frozenset({'Authorization'})
  `REDIRECT_STATUSES` = frozenset({300, 301, 302, 303, 307, 308})

class `azure.core.pipeline.policies.``ProxyPolicy`(proxies=None, **kwargs)

  Bases: `azure.core.pipeline.policies._base.SansIOHTTPPolicy`

  A proxy policy.

  Dictionary mapping protocol or protocol and host to the URL of the proxy to be used on each Request.

  Parameters: | proxies (dict) – Maps protocol or protocol and hostname to the URL of the proxy.

  Example:

  `on_request`(request)

    Is executed before sending the request from next policy.

    Parameters: | request (PipelineRequest) – Request to be modified before sent from next policy.

class `azure.core.pipeline.policies.``CustomHookPolicy`(**kwargs)

  Bases: `azure.core.pipeline.policies._base.SansIOHTTPPolicy`

  A simple policy that enable the given callback with the response.

  Keyword Arguments:
  | raw_response_hook (callback) – Callback function. Will be invoked on response.

  `on_request`(request)

    This is executed before sending the request to the next policy.

    Parameters: | request (PipelineRequest) – The PipelineRequest object.

  `on_response`(request, response)

    This is executed after the request comes back from the policy.

    Parameters:

    - request (PipelineRequest) – The PipelineRequest object.
    - response (PipelineResponse) – The PipelineResponse object.

class `azure.core.pipeline.policies.``DistributedTracingPolicy`(**kwargs)

  Bases: `azure.core.pipeline.policies._base.SansIOHTTPPolicy`

  The policy to create spans for Azure calls.

  Keyword Arguments:

  - network_span_namer – A callable to customize the span name
  - tracing_attributes – Attributes to set on all created spans

  `end_span`(request, response=None, exc_info=None)

    Ends the span that is tracing the network and updates its status.

  `on_exception`(request)

    Is executed if an exception is raised while executing the next policy.

    Developer can optionally implement this method to return True if the exception has been handled and should not be forwarded to the caller.

    This method is executed inside the exception handler.

    Parameters: | request (PipelineRequest) – The Pipeline request object
    Returns: | False by default, override with True to stop the exception.
    Return type: | bool

    Example:

  `on_request`(request)

    Is executed before sending the request from next policy.

    Parameters: | request (PipelineRequest) – Request to be modified before sent from next policy.

  `on_response`(request, response)

    Is executed after the request comes back from the policy.

    Parameters:

    - request (PipelineRequest) – Request to be modified after returning from the policy.
    - response (PipelineResponse) – Pipeline response object

  `TRACING_CONTEXT` = 'TRACING_CONTEXT'

class `azure.core.pipeline.policies.``RequestHistory`(http_request, http_response=None, error=None, context=None)

  Bases: `object`

  A container for an attempted request and the applicable response.

  This is used to document requests/responses that resulted in redirected/retried requests.

  Parameters:

  - http_request (HttpRequest) – The request.
  - http_response (HttpResponse) – The HTTP response.
  - error (Exception) – An error encountered during the request, or None if the response was received successfully.
  - context (dict) – The pipeline context.

class `azure.core.pipeline.policies.``HttpLoggingPolicy`(logger=None, **kwargs)

  Bases: `azure.core.pipeline.policies._base.SansIOHTTPPolicy`

  The Pipeline policy that handles logging of HTTP requests and responses.

  `on_request`(request)

    Logs HTTP method, url and headers. :param request: The PipelineRequest object. :type request: ~azure.core.pipeline.PipelineRequest

  `on_response`(request, response)

    Is executed after the request comes back from the policy.

    Parameters:

    - request (PipelineRequest) – Request to be modified after returning from the policy.
    - response (PipelineResponse) – Pipeline response object

  `DEFAULT_HEADERS_WHITELIST` = {'Accept', 'Cache-Control', 'Connection', 'Content-Length', 'Content-Type', 'Date', 'ETag', 'Expires', 'If-Match', 'If-Modified-Since', 'If-None-Match', 'If-Unmodified-Since', 'Last-Modified', 'Pragma', 'Request-Id', 'Retry-After', 'Server', 'Transfer-Encoding', 'User-Agent', 'traceparent', 'x-ms-client-request-id', 'x-ms-return-client-request-id'}
  `REDACTED_PLACEHOLDER` = 'REDACTED'

class `azure.core.pipeline.policies.``RequestIdPolicy`(**kwargs)

  Bases: `azure.core.pipeline.policies._base.SansIOHTTPPolicy`

  A simple policy that sets the given request id in the header.

  This will overwrite request id that is already defined in the request. Request id can be configured up front, where the request id will be applied to all outgoing operations, and additional request id can also be set dynamically per operation.

  Keyword Arguments:

  - request_id (str) – The request id to be added into header.
  - auto_request_id (bool) – Auto generates a unique request ID per call if true which is by default.

  Example:

  `on_request`(request)

    Updates with the given request id before sending the request to the next policy.

    Parameters: | request (PipelineRequest) – The PipelineRequest object

  `set_request_id`(value)

    Add the request id to the configuration to be applied to all requests.

    Parameters: | value (str) – The request id value.

class `azure.core.pipeline.policies.``AsyncHTTPPolicy`

  Bases: `abc.ABC`, `typing.Generic`

  An async HTTP policy ABC.

  Use with an asynchronous pipeline.

  Parameters: | next (AsyncHTTPPolicy or AsyncHttpTransport) – Use to process the next policy in the pipeline. Set when pipeline is instantiated and all policies chained.

  `send`(request: azure.core.pipeline.PipelineRequest)

    Abstract send method for a asynchronous pipeline. Mutates the request.

    Context content is dependent on the HttpTransport.

    Parameters: | request (PipelineRequest) – The pipeline request object.
    Returns: | The pipeline response object.
    Return type: | PipelineResponse

class `azure.core.pipeline.policies.``AsyncBearerTokenCredentialPolicy`(credential, *scopes, **kwargs)

  Bases: `azure.core.pipeline.policies._authentication._BearerTokenCredentialPolicyBase`, `azure.core.pipeline.policies._base.SansIOHTTPPolicy`

  Adds a bearer token Authorization header to requests.

  Parameters:

  - credential (TokenCredential) – The credential.
  - scopes (str) – Lets you specify the type of access needed.

  `on_request`(request: azure.core.pipeline.PipelineRequest)

    Adds a bearer token Authorization header to request and sends request to next policy.

    Parameters: | request (PipelineRequest) – The pipeline request object to be modified.
    Raises: | `ServiceRequestError`

class `azure.core.pipeline.policies.``AsyncRedirectPolicy`(**kwargs)

  Bases: `azure.core.pipeline.policies._redirect.RedirectPolicy`, `azure.core.pipeline.policies._base_async.AsyncHTTPPolicy`

  An async redirect policy.

  An async redirect policy in the pipeline can be configured directly or per operation.

  Keyword Arguments:

  - permit_redirects (bool) – Whether the client allows redirects. Defaults to True.
  - redirect_max (int) – The maximum allowed redirects. Defaults to 30.

  Example:

  `send`(request)

    Sends the PipelineRequest object to the next policy. Uses redirect settings to send the request to redirect endpoint if necessary.

    Parameters: | request (PipelineRequest) – The PipelineRequest object
    Returns: | Returns the PipelineResponse or raises error if maximum redirects exceeded.
    Return type: | PipelineResponse
    Raises: | ~azure.core.exceptions.TooManyRedirectsError if maximum redirects exceeded.

class `azure.core.pipeline.policies.``AsyncRetryPolicy`(**kwargs)

  Bases: `azure.core.pipeline.policies._retry.RetryPolicy`, `azure.core.pipeline.policies._base_async.AsyncHTTPPolicy`

  Async flavor of the retry policy.

  The async retry policy in the pipeline can be configured directly, or tweaked on a per-call basis.

  Keyword Arguments:

  - retry_total (int) – Total number of retries to allow. Takes precedence over other counts. Default value is 10.
  - retry_connect (int) – How many connection-related errors to retry on. These are errors raised before the request is sent to the remote server, which we assume has not triggered the server to process the request. Default value is 3.
  - retry_read (int) – How many times to retry on read errors. These errors are raised after the request was sent to the server, so the request may have side-effects. Default value is 3.
  - retry_status (int) – How many times to retry on bad status codes. Default value is 3.
  - retry_backoff_factor (float) – A backoff factor to apply between attempts after the second try (most errors are resolved immediately by a second try without a delay). Retry policy will sleep for: {backoff factor} * (2 ** ({number of total retries} - 1)) seconds. If the backoff_factor is 0.1, then the retry will sleep for [0.0s, 0.2s, 0.4s, …] between retries. The default value is 0.8.
  - retry_backoff_max (int) – The maximum back off time. Default value is 120 seconds (2 minutes).

  Example:

  `send`(request)

    Uses the configured retry policy to send the request to the next policy in the pipeline.

    Parameters: | request (PipelineRequest) – The PipelineRequest object
    Returns: | Returns the PipelineResponse or raises error if maximum retries exceeded.
    Return type: | PipelineResponse
    Raise: | ~azure.core.exceptions.AzureError if maximum retries exceeded.
    Raise: | ~azure.core.exceptions.ClientAuthenticationError if authentication fails

  `sleep`(settings, transport, response=None)

    Sleep between retry attempts.

    This method will respect a server’s `Retry-After` response header and sleep the duration of the time requested. If that is not present, it will use an exponential backoff. By default, the backoff factor is 0 and this method will return immediately.

    Parameters:

    - settings (dict) – The retry settings.
    - transport – The HTTP transport type.
    - response (PipelineResponse) – The PipelineResponse object.