├── .gitignore
├── README.md
├── LICENSE
└── simple-ga.py


/.gitignore:
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1 | # OS Related Files #
2 | *.DS_Store
3 | 


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/README.md:
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1 | # simple-ga
2 | Sample code for an incredibly simple genetic algorithm.
3 | 


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/LICENSE:
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 1 | The MIT License (MIT)
 2 | 
 3 | Copyright (c) 2015 Troy Squillaci
 4 | 
 5 | Permission is hereby granted, free of charge, to any person obtaining a copy
 6 | of this software and associated documentation files (the "Software"), to deal
 7 | in the Software without restriction, including without limitation the rights
 8 | to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 9 | copies of the Software, and to permit persons to whom the Software is
10 | furnished to do so, subject to the following conditions:
11 | 
12 | The above copyright notice and this permission notice shall be included in all
13 | copies or substantial portions of the Software.
14 | 
15 | THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 | IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 | FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
18 | AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 | LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
20 | OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
21 | SOFTWARE.
22 | 
23 | 


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/simple-ga.py:
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  1 | from fuzzywuzzy import fuzz
  2 | import random
  3 | import string
  4 | 
  5 | 
  6 | class Agent:
  7 | 
  8 |     def __init__(self, length):
  9 | 
 10 |         self.string = ''.join(random.choice(string.letters) for _ in xrange(length))
 11 |         self.fitness = -1
 12 | 
 13 |     def __str__(self):
 14 | 
 15 |         return 'String: ' + str(self.string) + ' Fitness: ' + str(self.fitness)
 16 | 
 17 | in_str = None
 18 | in_str_len = None
 19 | population = 20
 20 | generations = 10000
 21 | 
 22 | 
 23 | def ga():
 24 | 
 25 |     agents = init_agents(population, in_str_len)
 26 | 
 27 |     for generation in xrange(generations):
 28 | 
 29 |         print 'Generation: ' + str(generation)
 30 | 
 31 |         agents = fitness(agents)
 32 |         agents = selection(agents)
 33 |         agents = crossover(agents)
 34 |         agents = mutation(agents)
 35 | 
 36 |         if any(agent.fitness >= 90 for agent in agents):
 37 | 
 38 |             print 'Threshold met!'
 39 |             exit(0)
 40 | 
 41 | 
 42 | def init_agents(population, length):
 43 | 
 44 |     return [Agent(length) for _ in xrange(population)]
 45 | 
 46 | 
 47 | def fitness(agents):
 48 | 
 49 |     for agent in agents:
 50 | 
 51 |         agent.fitness = fuzz.ratio(agent.string, in_str)
 52 | 
 53 |     return agents
 54 | 
 55 | 
 56 | def selection(agents):
 57 | 
 58 |     agents = sorted(agents, key=lambda agent: agent.fitness, reverse=True)
 59 |     print '\n'.join(map(str, agents))
 60 |     agents = agents[:int(0.2 * len(agents))]
 61 | 
 62 |     return agents
 63 | 
 64 | 
 65 | def crossover(agents):
 66 | 
 67 |     offspring = []
 68 | 
 69 |     for _ in xrange((population - len(agents)) / 2):
 70 | 
 71 |         parent1 = random.choice(agents)
 72 |         parent2 = random.choice(agents)
 73 |         child1 = Agent(in_str_len)
 74 |         child2 = Agent(in_str_len)
 75 |         split = random.randint(0, in_str_len)
 76 |         child1.string = parent1.string[0:split] + parent2.string[split:in_str_len]
 77 |         child2.string = parent2.string[0:split] + parent1.string[split:in_str_len]
 78 | 
 79 |         offspring.append(child1)
 80 |         offspring.append(child2)
 81 | 
 82 |     agents.extend(offspring)
 83 | 
 84 |     return agents
 85 | 
 86 | 
 87 | def mutation(agents):
 88 | 
 89 |     for agent in agents:
 90 | 
 91 |         for idx, param in enumerate(agent.string):
 92 | 
 93 |             if random.uniform(0.0, 1.0) <= 0.1:
 94 | 
 95 |                 agent.string = agent.string[0:idx] + random.choice(string.letters) + agent.string[idx+1:in_str_len]
 96 | 
 97 |     return agents
 98 | 
 99 | 
100 | if __name__ == '__main__':
101 | 
102 |     in_str = 'TroySquillaci'
103 |     in_str_len = len(in_str)
104 |     ga()
105 | 


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