How to read a list of 1000 elements from a txt file in python and then sort it with Quicksort

As Jorge Arturo says in his commentary, it depends on the limiters that you have in your txt file. Assuming that each value is separated by a line break in your file then it would be something like the following.

arch = open('archivo.txt', 'r')

for linea in arch:
    arreglo.append(int(linea))

arch.close()

In order for this to be applicable, all lines in your file must be integer values too.

You open the file with open then read the text with read() and you convert your string in a list with split() , you can add your separator within split:

file = open(“testfile.text”, “r”) 
text = file.read() 
items = text.split(",")

in my example the text would be something like "a, b, c, d" and split convert it to ["a", "b", "c", "d"]

How is the file format? I'm going to assume it's a flat file with a value per line and what you're looking for is to load this into a list.

def read_file(file):
    """Lee un archivo de texto y devuelve una lista con sus lineas"""
    lista = []
    with open(file) as procfile:
      for line in procfile:
        lista.append(line.strip())
    return lista

Now if the file has a single line with values separated by ',' you can do this:

def read_file(file):
    """Lee un archivo de texto y devuelve una lista"""
    with open(file) as procfile:
      line = procfile.readline()
      return [i for i in line.split(',')]

def quicksort(arreglo,izq,der):
    i=izq
    j=der
    piv=arreglo[(izq + der)/2]

    while( i <= j ):
        while arreglo[i]<piv and j<=der:
            i=i+1
        while piv<arreglo[j] and j>izq:
            j=j-1
        if i<=j:
            aux = arreglo[i]; 
            arreglo[i] = arreglo[j]; 
            arreglo[j] = aux;
            i=i+1;  
            j=j-1;

        if izq < j:
          quicksort( arreglo, izq, j );
    if i < der:
        quicksort( arreglo, i, der );

def imprimeLista(arreglo,tam):
    for i in range(0,tam): print arreglo[i],



def leeLista():
    arreglo=[]
    a=int(raw_input("Ingresa el tamano del arreglo: "))

    #for i in range(0,a):
     #   arreglo.append(int(raw_input("Ingresa los valores %d : " % i)))

    arch = open('or.txt', 'r')

    for linea in arch:
        arreglo.append(linea.strip())

    arch.close()    

    pos=int(raw_input("Selecciona el pivote: "))
    return arreglo

A=leeLista()
tiempo_inicial = time()
quicksort(A,0,len(A)-1)
tiempo_final = time()
tiempo_ejecucion = tiempo_final - tiempo_inicial
print'El tiempo de ejecucion fue ::', tiempo_ejecucion
imprimeLista(A,len(A))

This is my code but it does not do the ordering just print the arrangement as it is

Result:

El tiempo de ejecucion fue :: 2.69412994385e-05
2,24,3,26,21,1, 4, 5, 29,6, 7, 8, 9, 10, 12, 13, 14, 15, 30,16, 17, 18, 19, 20, 22, 23, 25,  27, 28,11