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tag-letter-entropy.py
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tag-letter-entropy.py
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# coding: utf-8
# billdthompson@berkeley.edu
# wdt@princeton.edu
import pysnooper
import numpy as np
import pandas as pd
import json
import click
import logging
logging.basicConfig(format='%(levelname)s > %(message)s', level=logging.INFO)
@click.command()
@click.option('--datafile', '-d')
def run(datafile):
df = pd.read_csv(datafile)
# http://practicalcryptography.com/cryptanalysis/letter-frequencies-various-languages/english-letter-frequencies/
with open('letter-freq-dict.txt', 'r') as f:
letterfreqs = json.loads(f.read())
# @pysnooper.snoop()
def logletterfreq(row):
if not isinstance(row.word, str):
return None
letters = list(row.word.upper())
freqs = map(letterfreqs.get, letters)
probs = np.fromiter(freqs, dtype = float) / 100.
mean = probs.mean()
logmean = np.log(mean)
return logmean
df['logletterfreq'] = df.apply(logletterfreq, axis = 1)
df.to_csv(datafile.replace('.csv', '-logletterfreq.csv'))
if __name__ == '__main__':
run()