Python import statements breaking print value headed to php code

I am making a website with php and a coworker is providing a python script that my php code will execute through shell_exec(). His python script uses a print statement to send the output needed to my php code. We noticed through the creation of a simple test python script, no printed value were returned when the following import statements were included...

import pypyodbc
from collections import OrderedDict
import argparse
import pymysql

but when these imports were excluded, we were able to get output. Any ideas as to why this may be happening? Thanks in advance!