Looped sed statement - weird output

Question

I wrote a small script that will recursively go through all *.py files within a directory and replace specific entries in the files.

So the files and their current content:

find . -name "*.py" -exec ls "{}" \; -exec cat "{}" \;

and that returns this:

./1/File1.py
import sys

./2/3/File3.py
import sys
sys.exit(1)

./6/7/File7.py
import sys
sys.exit()

./File0.py
import sys

Now the script I wrote is this:

for file in $(find . -name "*.py")
do
    echo "$file"
    sed 's/sys.exit.*/os_.exit()/g;s/import sys/&\nimport os/g' "$file"
done

Now if I ran those sed commands on their own, I would get my desired output. If I run them both together within my script, or like so:

find . -name "*.py" -exec sed 's/sys.exit.*/os_.exit()/g' "{}" \; -exec sed 's/import sys/&\nimport os/g' "{}" \;

it would end up duplicating my output like this:

./1/File1.py
import sys
import sys
import os

./2/3/File3.py
import sys
os_.exit()
import sys
import os
sys.exit(1)

./6/7/File7.py
import sys
os_.exit()
import sys
import os
sys.exit()

./File0.py
import sys
import sys
import os

Can someone point out what I'm doing wrong?

EDIT: thanks to the link posted by don_crissti, I have edited the script to actually execute a 'one-liner'. I have posted this below, thanks to the input from all who commented it has resolved my issue.

find . -name "*.py" -exec ls "{}" \; -exec sed 's/sys.exit.*/os_.exit()/g;s/import sys/&\nimport os/g' "{}" \;

Answer 1

The output is as should be expected, because each of the two sed commands operates on the same unmodified input text. In order to obtain the output which the inquirer expected, the two substitute commands should be combined in one invocation of sed:

... -exec sed -e 's/sys.exit.*/os_.exit()/g' -e 's/import sys/&\nimport os/g' "{}" \;

or

... -exec sed 's/sys.exit.*/os_.exit()/g;s/import sys/&\nimport os/g' "{}" \;