I want to run this script

python cgenff_charmm2gmx.py JZ4 jz4_fix.mol2 jz4.str charmm36-nov2018.ff

I am using this script on cluster computer so, I can't update any version on python..

PLEASE NOTE: This script requires a Python 2.7.x version and the NetworkX package, version 1.11.x - it is incompatible with NetworkX 2.x and the script will fail.

IN SUCH CASE, I INPUT MY TEXT HERE... BUT GOT THIS ERROR

[reetesh@coe ~]$ 
[reetesh@coe ~]$ python2.7
Python 2.7.13 (default, Mar  2 2017, 18:43:14) 
[GCC 5.1.0] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> python cgenff_charmm2gmx.py JZ4 jz4_fix.mol2 jz4.str charmm36-nov2018.ff
  File "<stdin>", line 1
    python cgenff_charmm2gmx.py JZ4 jz4_fix.mol2 jz4.str charmm36-nov2018.ff
                           ^
SyntaxError: invalid syntax
>>>

thanks in advance to figure out this issue.