Bash coproc with python

I am playing with the coproc of Bash and I am failing to understand something. I started with the following example: # Example#1

$ coproc MY_BASH { bash; }
 95244
$ echo 'ls -l; echo EOD' >&"${MY_BASH}"
$ is_done=false; while [[ "$is_done" != "true" ]]; do
>   read var    if [[ $var == "EOD" ]]; then
>      is_done="true"
>   else
>      echo $var
>   fi
> done
total 0
-rw-rw-r-- 1 username username 0 Nov 11 13:00 file10.txt
-rw-rw-r-- 1 username username 0 Nov 11 13:00 file1.txt
-rw-rw-r-- 1 username username 0 Nov 11 13:00 file2.txt
-rw-rw-r-- 1 username username 0 Nov 11 13:00 file3.txt
-rw-rw-r-- 1 username username 0 Nov 11 13:00 file4.txt
-rw-rw-r-- 1 username username 0 Nov 11 13:00 file5.txt
-rw-rw-r-- 1 username username 0 Nov 11 13:00 file6.txt
-rw-rw-r-- 1 username username 0 Nov 11 13:00 file7.txt
-rw-rw-r-- 1 username username 0 Nov 11 13:00 file8.txt
-rw-rw-r-- 1 username username 0 Nov 11 13:00 file9.txt
$

Here we can see that the current Bash shell is able to create a coprocess and interact with it. # Example 2 In this case, I switch from a bash coprocess to a python coprocess:

$ coproc MY_BASH { python; }
 95244
$ echo 'print("hello"); print("EOD");' >&"${MY_BASH}"
$ is_done=false; while [[ "$is_done" != "true" ]]; do
>   read var    if [[ $var == "EOD" ]]; then
>      is_done="true"
>   else
>      echo $var
>   fi
> done

In this scenario the program hangs and gets blocked. I have the impression that I am forgetting to send something in the input. Any help to better understand what is going on will be appreciated.