Combine shell and python code

Question

Currently, I have following code works:

a.sh

echo "start"
export abc="hello"
a=`python a.py`
echo $a
echo "end"

a.py

import os
print os.getenv('abc')*2

Above, my shell script need one python script' help to handle something then back the answer to shell script.

Although it works, we need to write another python file, the requirement is to afford single file to users, so how it makes, I remember I have once saw some kind of realize which combine shell and python code, could anyone also know that & give me some clue?

• syntonym: Why not write everything in python?
• Guy: backticks aren't recommended, by the way, $( cmd ) is. Its easier for nesting etc.
• atline: @backticks, why backticks not recommended?
• Guy: It's the same character to start and end makes them more difficult to use correctly. The way I suggested does the same thing, but with less escaping issues. stackoverflow.com/q/9405478
• atline: @Guy, i knew both of them, but did not realize the difference between them, really a windfall, thanks.

Answer 1

You could use python's -c option in your a.sh file:

echo "start"
export abc="hello"
a=$(python -c "import os ; print os.getenv('abc') * 2")
echo $a
echo "end"

Answer 2

a.sh

echo "start"
export abc="hello"
a=`python <<- EOF
import os
print os.getenv('abc')*2
EOF`
echo $a
echo "end"

• Guy: you dont need cat there, you can just use python <<- EOF ...