Type, I have a list like this:
lista = [1,1,2,3,3,3]
And I want to order it to stay
lista = [3,3,3,1,1,2]
That is, the most occurring values would be at the beginning of the list, while the values less occurring at the end. I've tried several functions, but it did not work.
Try this:
from collections import Counter
lista = [1,1,2,3,3,3]
print [item for items, c in Counter(lista).most_common() for item in [items] * c]
# [3, 3, 3, 1, 1, 2]
If you do not want to use libraries, here's an idea using dictionaries:
First I create a dictionary with the occurrences
lista = [1,1,2,3,3,3]
ocorrencias = {}
for numero in lista:
if numero in ocorrencias: #Se o numero ja esta no dicionario
ocorrencias[numero] += 1
else: #Se não está, adiciono em ocorrencias
ocorrencias[numero] = 1
#OU ocorrencias.update({numero:1})
>>> print ocorrencias
{1: 2, 2: 1, 3: 3}
Then I create the ordered list from the dictionary of occurrences
def pega_maior_ocorrencia(dicionario):
maior_ocorrencia = 0
chave = None
for key, value in dicionario.iteritems(): #Python2.X
#for key, value in d.items(): #Python3.X
if value > maior_ocorrencia:
maior_ocorrencia = value
chave = key
del dicionario[chave] #deleta do dict mesmo dentro da função
return [chave]*maior_ocorrencia
lista_ocorrencias = []
for i in range(len(ocorrencias)):
lista_ocorrencias += pega_maior_ocorrencia(ocorrencias)
>>> print lista_ocorrencias
[3, 3, 3, 1, 1, 2]