⌨ Quickstart TL;DR¶

Keeping someone from using your unfinished feature¶

In [1]:

from fastfeatureflag.feature_flag import feature_flag

from fastfeatureflag.feature_flag import feature_flag

In [2]:

def not_finished_feature():
    return "Not finished"

not_finished_feature()

def not_finished_feature(): return "Not finished" not_finished_feature()

Out[2]:

'Not finished'

In [3]:

@feature_flag()  # == @feature_flag("off")
def not_finished_feature():
    return "Not finished"

not_finished_feature()

@feature_flag() # == @feature_flag("off") def not_finished_feature(): return "Not finished" not_finished_feature()

---------------------------------------------------------------------------
NotImplementedError                       Traceback (most recent call last)
Cell In[3], line 5
      1 @feature_flag()  # == @feature_flag("off")
      2 def not_finished_feature():
      3     return "Not finished"
----> 5 not_finished_feature()

File /opt/hostedtoolcache/Python/3.12.0/x64/lib/python3.12/site-packages/fastfeatureflag/feature_flag_configuration.py:62, in FeatureFlagConfiguration.__call__(self, *args, **kwargs)
     59 if self.feature.shadow:
     60     return self._shadow_function(*args, **kwargs)
---> 62 return self._decorated_function(*args, **kwargs)

File /opt/hostedtoolcache/Python/3.12.0/x64/lib/python3.12/site-packages/fastfeatureflag/feature_flag_configuration.py:202, in FeatureFlagConfiguration._decorated_function(self, *args, **kwargs)
    199     if self.feature.response:
    200         return self.feature.response
--> 202     raise NotImplementedError("Feature not implemented") from None
    204 if (
    205     self.feature.activation == "on"
    206     or os.environ.get(self.feature.activation) == "on"
    207 ):
    208     self._options = self._options | kwargs

NotImplementedError: Feature not implemented

activate the feature

In [4]:

@feature_flag("on")
def not_finished_feature():
    return "Not finished"

not_finished_feature()

@feature_flag("on") def not_finished_feature(): return "Not finished" not_finished_feature()

Out[4]:

'Not finished'

Response differently if feature is deactivated¶

In [5]:

@feature_flag("off", response="Go on")
def not_finished_feature():
    return "Not finished"

not_finished_feature()

@feature_flag("off", response="Go on") def not_finished_feature(): return "Not finished" not_finished_feature()

Out[5]:

'Go on'

In [6]:

def mocked_data():
    return {"mocked":"data"}

@feature_flag("off", response=mocked_data())
def not_finished_feature():
    return "Not finished"

not_finished_feature()

def mocked_data(): return {"mocked":"data"} @feature_flag("off", response=mocked_data()) def not_finished_feature(): return "Not finished" not_finished_feature()

Out[6]:

{'mocked': 'data'}

Group features by naming them¶

In [7]:

@feature_flag("off", name="grouped_features")
def not_finished_feature_one():
    return "Not finished feature one"

@feature_flag()
def not_finished_feature_two(name="grouped_features"):
    return "Not finished feature two"

@feature_flag("off", name="grouped_features") def not_finished_feature_one(): return "Not finished feature one" @feature_flag() def not_finished_feature_two(name="grouped_features"): return "Not finished feature two"

In [8]:

not_finished_feature_one()

not_finished_feature_one()

---------------------------------------------------------------------------
NotImplementedError                       Traceback (most recent call last)
Cell In[8], line 1
----> 1 not_finished_feature_one()

File /opt/hostedtoolcache/Python/3.12.0/x64/lib/python3.12/site-packages/fastfeatureflag/feature_flag_configuration.py:62, in FeatureFlagConfiguration.__call__(self, *args, **kwargs)
     59 if self.feature.shadow:
     60     return self._shadow_function(*args, **kwargs)
---> 62 return self._decorated_function(*args, **kwargs)

File /opt/hostedtoolcache/Python/3.12.0/x64/lib/python3.12/site-packages/fastfeatureflag/feature_flag_configuration.py:202, in FeatureFlagConfiguration._decorated_function(self, *args, **kwargs)
    199     if self.feature.response:
    200         return self.feature.response
--> 202     raise NotImplementedError("Feature not implemented") from None
    204 if (
    205     self.feature.activation == "on"
    206     or os.environ.get(self.feature.activation) == "on"
    207 ):
    208     self._options = self._options | kwargs

NotImplementedError: Feature not implemented

In [9]:

not_finished_feature_two()

not_finished_feature_two()

---------------------------------------------------------------------------
NotImplementedError                       Traceback (most recent call last)
Cell In[9], line 1
----> 1 not_finished_feature_two()

File /opt/hostedtoolcache/Python/3.12.0/x64/lib/python3.12/site-packages/fastfeatureflag/feature_flag_configuration.py:62, in FeatureFlagConfiguration.__call__(self, *args, **kwargs)
     59 if self.feature.shadow:
     60     return self._shadow_function(*args, **kwargs)
---> 62 return self._decorated_function(*args, **kwargs)

File /opt/hostedtoolcache/Python/3.12.0/x64/lib/python3.12/site-packages/fastfeatureflag/feature_flag_configuration.py:202, in FeatureFlagConfiguration._decorated_function(self, *args, **kwargs)
    199     if self.feature.response:
    200         return self.feature.response
--> 202     raise NotImplementedError("Feature not implemented") from None
    204 if (
    205     self.feature.activation == "on"
    206     or os.environ.get(self.feature.activation) == "on"
    207 ):
    208     self._options = self._options | kwargs

NotImplementedError: Feature not implemented

we want to reuse the feature name, therefore we have to clean all registered features

In [10]:

not_finished_feature_one.clean()

not_finished_feature_one.clean()

changing the activation of the first appearing feature_flag activates both features

In [11]:

@feature_flag("on", name="grouped_features")
def not_finished_feature_one():
    return "Not finished feature one"

@feature_flag(name="grouped_features")
def not_finished_feature_two():
    return "Not finished feature two"

@feature_flag("on", name="grouped_features") def not_finished_feature_one(): return "Not finished feature one" @feature_flag(name="grouped_features") def not_finished_feature_two(): return "Not finished feature two"

In [12]:

not_finished_feature_one()

not_finished_feature_one()

Out[12]:

'Not finished feature one'

In [13]:

not_finished_feature_two()

not_finished_feature_two()

Out[13]:

'Not finished feature two'

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Last update: October 28, 2023
Created: October 28, 2023