Login to Perforce server, create a workspace and sync code to specific changelist number.

Sample for p4python

#!/env/bin/python

from P4 import P4, P4Exception
import json

p4 = P4()
p4.user = "charz"
p4.password = "mypassword"
p4.port = "tcp:192.168.1.2:1666"
p4.client = "auto-build"
p4.connect()
print p4


try:
    client = p4.fetch_client("auto-build")
    client["Root"] = "/home/charz/Work/Build_root"
    client["View"] = [ "//depot/tools/... //%s/tools... "% p4.client , ] 
    p4.save_client(client)
    p4.run_login()

#    aa = p4.run_sync('-f')
    aa = p4.run('sync', '-f', '@2022')
    a1 = p4.run('changes', '-m1', '%s/tools/...#have'% client["Root"])
    print json.dumps(a1, indent=2)

#    print "========================================"
#    bb = p4.run('sync', '@2028')
#    print json.dumps(bb, indent=2)
#    a2 = p4.run('changes', '-l', '-m1', '%s/tools/...#have'% client["Root"])
#    print json.dumps(a2, indent=2)
#    a2 = p4.run('changes', '-l', '-m10', '%s/tools/...#have'% client["Root"])
#    print json.dumps(a2, indent=2)


    p4.disconnect()
except P4Exception as e:
    print e