Execute terminal command and get output in python.

get-terminal-output.py

# For short output.
import subprocess
cmd = "git branch | grep '*' | cut -d ' ' -f2"
output = subprocess.Popen(cmd,stdout=subprocess.PIPE,shell=True).communicate()[0]
print(output.strip()) # For single line output.

# For long output.
import subprocess
import tempfile
cmd = "git branch | grep '*' | cut -d ' ' -f2"
with tempfile.TemporaryFile() as tempf:
    proc = subprocess.Popen(cmd, stdout=tempf,shell=True)
    proc.wait()
    tempf.seek(0)
    print(tempf.read())

I have a shell script which I am executing from git bash here.
I automated the same using python subprocess which will launch gitbash and execute the shell script.
I am not able to get the gitbash console output to python console.
I tried above approach it did not work, all I get for print(temp.read()) is b' '