linux系统安装了python中，但是为什么执行有问题

执行python命令  报错如下：nohup python -u py_write_excel.py >>nouhp2.out 2>&1 &

[analyse@host-192-168-1-24 batch]$ more nouhp2.out 
Traceback (most recent call last):
  File "py_write_excel.py", line 5, in 
    import cx_Oracle
ImportError: No module named cx_Oracle
Traceback (most recent call last):
  File "py_write_excel.py", line 5, in 
    import cx_Oracle
ImportError: No module named cx_Oracle
nohup: ignoring input
Traceback (most recent call last):
  File "py_write_excel.py", line 5, in 
    import cx_Oracle
ImportError: No module named cx_Oracle

原因是python，命令  是默认用的python2，python2中默认是没有

cx_Oracle这个模块的，，如果改成python3就可以执行了。因为python3中内置

cx_Oracle这个模块