python - library problems

i'm comparatively new python am carrying problems programming scapy, python network plan tool. however, i can't tell it's many scapy problem being-a-python-newbie problem. , give illustration way i'm means run possess machine:

#! /usr/bin/env python

import sys
from scapy import sr1,ip,icmp

p=sr1(ip(dst=sys.argv[1])/icmp())
if p:
    p.show()

to i get:

traceback (most new last):
  record "test.py", line 4, <module>
    scapy import sr1,ip,icmp
importerror: can't import name sr1

so doubt following is: installing python libraries, i need change route anything similar? also, there something i run interpreter tell me essence scapy package? i run from scapy import * only fine, nonetheless given i have thought what's inside it, it's tough it.