Vim vi how to reload a file your editing

#!/usr/bin/python
print "Hex"

li = []
for i in range(128,256) :
li.append(hex(i))
for i in range(0,128) :
li.append(hex(i))

javastring = "String bytelookup = { "
for i in li :
javastring = javastring + "\""+ i +"\"" + ", "


javastring = javastring[0:-2] + " }"

print javastring