How to pass parameters into php executed in python?

import subprocess
def php(code):
    p = subprocess.Popen(["php","-r", code],
                         stdout=subprocess.PIPE, stderr=subprocess.PIPE)
    out = p.communicate() #returns a tuple (stdoutdata, stderrdata)
    if out[1] != b'': raise Exception(out[1].decode('UTF-8'))
    return out[0].decode('UTF-8')
val = str(1234)
code = """ \
function my_encoder($in){
    $out = base_convert($in,16,36);
return ($out);}

print(my_encoder('"""+{val}+"""'));
"""
print(php(code))

print(my_encoder('"""+val+"""'));
"""