python计算程序开始到程序结束的运行时间和程序运行的CPU时间

import datetime
starttime = datetime.datetime.now()
#long running
endtime = datetime.datetime.now()
print (endtime - starttime).seconds

start = time.time()
run_fun()
end = time.time()
print end-start

start = time.clock()
run_fun()
end = time.clock()
print end-start