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Dev guide

Decide methods for the Python SDK

An overview of the decide methods for the Python SDK, which can be used to return a flag decision for a user in Optimizely Feature Experimentation.

Use the Decide methods to return flag decisions for a user. The flag decision includes flag enabled/disabled status and flag variation.

This page describes the following Decide methods:

For details about the options you can set for Decide methods, see:

Decide

Version

SDK 3.7 and higher

Description

Returns a decision result for a flag key for a user. The decision result is returned in an OptimizelyDecision object and contains all data required to deliver the flag rule.

Decide is a method of the UserContext object. See OptimizelyUserContext for details.

See the OptimizelyDecision for details of the returned decision object.

Parameters

The following table describes parameters for the Decide method:

ParameterTypeDescription
flag_keyStringThe key of the feature flag
options (optional)ArrayArray of OptimizelyDecideOption enums. See following table.

Returns

The Decide method returns an OptimizelyDecision object. For more information, see OptimizelyDecision.

If the method encounters a critical error (SDK not ready, invalid flag key, etc), then it returns a decision with a null Variation Key field and populates the Reasons field with error messages (regardless of the Include Reasons option).

Example Decision

The following is an example of calling the Decide method and accessing the returned OptimizelyDecision object:

from optimizely import optimizely 
optimizely_client = optimizely.Optimizely(sdk_key = "<YOUR_SDK_KEY>")

#create the user and decide which flag rule and variation they bucket into 
user = optimizely_client.create_user_context("user123", {"logged_in":True})
decision = user.decide("product_sort")

#flag enabled state:
enabled = decision.enabled

#variable value:
value1 =  decision.variables["sort_method"]

#all variable values
all_var_values = decision.variables

#variation. if null, decision fail with a critical error
variation_key = decision.variation_key

#flag decision reasons
reasons = decision.reasons

#user for which the decision was made
user_context = decision.user_context

Side Effects

Invokes the DECISION notification listener if this listener is enabled.

OptimizelyDecideOption

The following example shows how you can set options individually on any Decide method, or as global defaults when you instantiate the Optimizely client.

from optimizely import optimizely
from optimizely.decision.optimizely_decide_option import OptimizelyDecideOption

#set global default decide options when initializing the client
optimizely_client = optimizely.Optimizely(
  sdk_key = "<YOUR_SDK_KEY>",
  options = [OptimizelyDecideOption.DISABLE_DECISION_EVENT])


#set additional options in a decide call
user = optimizely.create_user_context("user123")
decision = user.decide_all(
  options = [OptimizelyDecideOption.ENABLED_FLAGS_ONLY,
             OptimizelyDecideOption.IGNORE_USER_PROFILE_SERVICE])

The following table shows details for the options you can set on Decide methods.

OptimizelyDecideOption enumIf set:
DecideOption.DISABLE_DECISION_EVENTPrevents the visitor from firing an impression while still being served the variation, which disables displaying results of the Decide method on the Results page.

This setting can be why the Decision Event Dispatched enum is false in the returned OptimizelyDecision object or the DECIDE notification listener payload.
DecideOption.ENABLED_FLAGS_ONLYReturn decisions for enabled flags only. This is a valid option only for methods that decide multiple flags, like the Decide All method. This option is ignored if it is invalid. When this option is not set, the SDK returns all decisions regardless of whether the flag is enabled or not.
DecideOption.IGNORE_USER_PROFILE_SERVICEWhen set, the SDK bypasses user profile service (UPS) (both lookup and save) for the decision.

When this option is not set, UPS overrides audience targeting, traffic allocation, and experiment mutual exclusion groups.
DecideOption.INCLUDE_REASONSReturn log messages in the Reasons field of OptimizelyDecision object. Note that unlike info or debug messages, critical error messages are always returned, regardless of this setting.
DecideOption.EXCLUDE_VARIABLESExclude flag variable values from the decision result. Use this option to minimize the returned decision by skipping large JSON variables.

Decide All

Returns decisions for all active (unarchived) flags for a user.

See OptimizelyDecision for details.

Version

SDK v3.7 and higher

Description

Use the Decide All method to return a map of flag decisions for a user.

Parameters

The following table describes parameters for the Decide All method:

ParameterTypeDescription
options (optional)ArrayArray of OptimizelyDecideOption enums. See Decide Parameters.

Returns

The Decide All method returns a map of OptimizelyDecisions. For more information, see OptimizelyDecision.

If the method fails for all flags (for example, the SDK is not ready or the user context is invalid), then it returns an empty map. If the method detects an error for a specific flag, it returns error messages in the Reasons field of the decision for that flag.

Examples

The following is an example of getting flags for the user with the Decide All call:

from optimizely.decision.optimizely_decide_option import OptimizelyDecideOption
 
# make decisions for all active (unarchived) flags in the project for a user
decisions = user.decide_all()

# or only for enabled flags  
decisions = user.decide_all([OptimizelyDecideOption.ENABLED_FLAGS_ONLY])

flag_keys = decisions.keys
flag_decisions = decisions.values
decision_for_flag_1 = decisions["flag_1"]

Invokes the DECISION notification listener for each decision if this listener is enabled.

Decide For Keys

The Decide For Keys method makes decisions for a user for specified flag keys.

Version

SDK v3.7 and higher

Description

Get a map of flag decisions for specific flag keys.

Parameters

The following table describes parameters for the Decide For Keys method:

ParameterTypeDescription
keysArrayArray of string flag keys.
options (optional)ArrayArray of OptimizelyDecideOption enums. See OptimizelyDecideOption.

Returns

Returns a map of OptimizelyDecisions. For more information, see OptimizelyDecision.

If the method fails for all flags (for example, the SDK is not ready or the user context is invalid), then it returns an empty map. If the method detects an error for a specific flag, it returns error messages in the Reasons field of the decision for that flag.

Example

The following is an example of getting specified flags for the user:

from optimizely.decision.optimizely_decide_option import OptimizelyDecideOption

# make a decisions for specific flags if enabled
decisions = user.decide_for_keys(["flag_1", "flag_2"], [OptimizelyDecideOption.ENABLED_FLAGS_ONLY])

decision_for_flag_1 = decisions["flag_1"]
decision_for_flag_2 = decisions["flag_2"]

Side effects

Invokes the DECISION notification listener for each decision if this listener is enabled.

Source files

The language and platform source files containing the implementation for Python are available on GitHub.