You just need to import it, as any other Python module.
from scapy.layers.inet import IP, ICMP
from scapy.sendrecv import sr
import sys
sr(IP(dst=sys.argv[1])/ICMP())
Or if you want to import everything at once:
import scapy.all as scapy
import sys
scapy.sr(scapy.IP(dst=sys.argv[1])/scapy.ICMP())
[...]
Or if you want to code exactly as in the Scapy console:
from scapy.all import *
import sys
sr(IP(dst=sys.argv[1])/ICMP())