fout = open('names.txt', 'w')

output = []
name = input("Please enter your name (or 0 to stop): ")
while name != "0":
    birthdate = input("Birthdate: ")
    color = input("Favorite color: ")
    output.append('\t'.join((name, birthdate, color)))

    name = input("Please enter your name (or 0 to stop): ")

fout.writelines(output)
fout.close()