How to send Ctrl+C to a child bash process on Windows?

Environment:

• Ubuntu 16.04 on Windows 10 1709
• Python 3.6

Consider this bash script:

#!/usr/bin/env bash

ping localhost

I start it from Windows command prompt:

> bash test.sh

When I press Ctrl+C, bash stops and exits cleanly:

> bash test.sh
PING localhost (127.0.0.1) 56(84) bytes of data.
64 bytes from localhost (127.0.0.1): icmp_seq=1 ttl=128 time=0.156 ms
64 bytes from localhost (127.0.0.1): icmp_seq=2 ttl=128 time=0.178 ms
^C
--- localhost ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 1001ms
rtt min/avg/max/mdev = 0.156/0.167/0.178/0.011 ms

However, if I start it from Python script, then it seems that there is no way to stop the child process cleanly. Here is the script:

#!/usr/bin/env python3

import subprocess
import signal

cmd = ['bash', 'test.sh']
p = subprocess.Popen(cmd)

while p.poll() is None:
    try:
        p.wait(2)
    except subprocess.TimeoutExpired:
        print('{0}: p.send_signal(signal.CTRL_C_EVENT)'.format(p.pid))
        p.send_signal(signal.CTRL_C_EVENT)
    except KeyboardInterrupt as e:
        print(e)
print('{0}: {1}'.format(p.pid, p.returncode))

Output:

> python module1.py
PING localhost (127.0.0.1) 56(84) bytes of data.
64 bytes from localhost (127.0.0.1): icmp_seq=1 ttl=128 time=0.193 ms
64 bytes from localhost (127.0.0.1): icmp_seq=2 ttl=128 time=0.255 ms
2316: p.send_signal(signal.CTRL_C_EVENT)

2316: 3221225786

As you can see, the exit code is 3221225786, aka 0xC000013A or STATUS_CONTROL_C_EXIT. Also, ping process didn't exit by itself, but was rather killed: no summary.

Is there any clean way to stop WSL bash process from Python?