mirror of
https://github.com/creyD/entro.py.git
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58 lines
1.7 KiB
Python
58 lines
1.7 KiB
Python
import math
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# Calculates the entropy of a given string
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# Returns the entropy and an alphabet with the calculated probabilities
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def calculateEntropy(input_string):
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alphabet, alphabet_size, entropy = {}, len(input_string), 0
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for char in input_string:
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if char in alphabet:
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alphabet[char] += 1
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else:
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alphabet[char] = 1
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for char in alphabet:
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alphabet[char] = alphabet[char] / alphabet_size
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entropy -= alphabet[char] * math.log(alphabet[char], 2)
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max_entropy = - len(alphabet) * (1 / len(alphabet) * math.log(1 / len(alphabet), 2))
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return entropy, alphabet, max_entropy
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# Calculates the entropy of a given string
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# Returns only the entropy in bits as this is the minimal function
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def calculateEntropyMin(input_string):
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alphabet, alphabet_size, entropy = {}, len(input_string), 0
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for char in input_string:
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if char in alphabet:
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alphabet[char] += 1
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else:
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alphabet[char] = 1
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for char in alphabet:
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i = alphabet[char] / alphabet_size
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entropy -= i * math.log(i, 2)
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return entropy
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# Outputs a given entropy including the original text and the alphabet with probabilities
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def printEntropy(original_string, entropy_value, alphabet_dict, simple_bool, max_value):
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print('---')
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if not simple_bool:
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print('Content: ' + original_string)
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print('Probabilities: ' + str(alphabet_dict))
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print('Entropy: ' + str(entropy_value) + ' bits')
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if max_value:
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print('Maximum Entropy: ' + str(max_value) + ' bits')
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print('---')
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# Reads a file by a given path
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def readEntropyFile(path_string):
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f = open(path_string, 'r')
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content = f.read().replace('\n', ' ')
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f.close()
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return content.strip()
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