Alterado

est.py

# -*- coding: utf-8 -*-
import dataset
from scipy import std, var, mean


db = dataset.connect('mysql://root@localhost/luciana')
table = db['prodeaf']

def calculate(length=None):
    size = length
    times = []
    words = table.find(word_size=size)
    qtd = table.count('word_size = %d' % size)

    for w in words:
        time = (w['time_translate']-1000)/1000
        times.append(time)

    # Imprimindo a variância e desvio padrão
    print("Tamanho: {}, QTD: {}, Média: {}, Variância: {}, desvio padrão: {}".format(
        size, qtd, mean(times), var(times), std(times)))


for n in range(1, 20):
    calculate(n)