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## Quickstart
They say [a good example is worth] 100 pages of API documentation, a
million directives, or a thousand words.
Well, "they" probably lie... but here's an example anyway:
```python
from transitions import Machine
import random
class NarcolepticSuperhero(object):
# Define some states. Most of the time, narcoleptic superheroes are
just like
# everyone else. Except for...
states = ['asleep', 'hanging out', 'hungry', 'sweaty', 'saving the
world']
def __init__(self, name):
# No anonymous superheroes on my watch! Every narcoleptic superhero
gets
# a name. Any name at all. SleepyMan. SlumberGirl. You get the
idea.
self.name = name
# What have we accomplished today?
self.kittens_rescued = 0
# Initialize the state machine
self.machine = Machine(model=self,
states=NarcolepticSuperhero.states, initial='asleep')
# Add some transitions. We could also define these using a static
list of
# dictionaries, as we did with states above, and then pass the list
to
# the Machine initializer as the transitions= argument.
# At some point, every superhero must rise and shine.
self.machine.add_transition(trigger='wake_up', source='asleep',
dest='hanging out')
# Superheroes need to keep in shape.
self.machine.add_transition('work_out', 'hanging out', 'hungry')
# Those calories won't replenish themselves!
self.machine.add_transition('eat', 'hungry', 'hanging out')
# Superheroes are always on call. ALWAYS. But they're not always
# dressed in work-appropriate clothing.
self.machine.add_transition('distress_call', '*', 'saving the
world',
before='change_into_super_secret_costume')
# When they get off work, they're all sweaty and disgusting. But
before
# they do anything else, they have to meticulously log their latest
# escapades. Because the legal department says so.
self.machine.add_transition('complete_mission', 'saving the world',
'sweaty',
after='update_journal')
# Sweat is a disorder that can be remedied with water.
# Unless you've had a particularly long day, in which case... bed
time!
self.machine.add_transition('clean_up', 'sweaty', 'asleep',
conditions=['is_exhausted'])
self.machine.add_transition('clean_up', 'sweaty', 'hanging out')
# Our NarcolepticSuperhero can fall asleep at pretty much any time.
self.machine.add_transition('nap', '*', 'asleep')
def update_journal(self):
""" Dear Diary, today I saved Mr. Whiskers. Again. """
self.kittens_rescued += 1
@property
def is_exhausted(self):
""" Basically a coin toss. """
return random.random() < 0.5
def change_into_super_secret_costume(self):
print("Beauty, eh?")
```
There, now you've baked a state machine into `NarcolepticSuperhero`. Let's
take him/her/it out for a spin...
```python
>>> batman = NarcolepticSuperhero("Batman")
>>> batman.state
'asleep'
>>> batman.wake_up()
>>> batman.state
'hanging out'
>>> batman.nap()
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