Python - Estudiante

Hola! Quisiera saber como arreglar este código sin utilizar el break y el range :(
mensaje = input("Ingrese su frase:")
mensaje_n = ""
partes = True
largo = len(mensaje)
i = 0
while partes:
p = ""
for n in range(i,largo):
if frase[n] == " ":
i = n + 1
break
p = p + frase[n]
if not "." in p and len(p)>=6:
p2 = ""
for l in p:
if l != "a" and l != "e" and l != "i" and l != "o" and l != "u":
p2 = p2+l
elif len(p)>=7:
p2 = ""
for l in p:
if l != "a" and l != "e" and l != "i" and l != "o" and l != "u":
p2=p2+l
else:
p2 = p
if not "." in p2 and p!=frase.split(" ")[-1]:
txt1 = txt1 + p2 + " "
else:
txt1 = txt1 + p2
if n == len(frase)-1:
break
print(mensaje_n)