Python: TypeError while searching in a string -

when run code:

    stdout = popen(callbackquery, shell=true, stdout=pipe).stdout     output = stdout.read()     if output.find("no records found matched search criteria") == -1:         print(output)     else:         # nothing         print("it's fine") 

i following error:

   if output.find("no records found matched search criteria") == -1: typeerror: 'str' not support buffer interface 

i understand character encoding don't know , how need convert this?

for people wondering why issue occured. subprocess documentation -

if universal_newlines true, file objects stdin, stdout , stderr opened text streams in universal newlines mode, described above in used arguments, otherwise opened binary streams.

the default value universal_newlines false, means stdout binary stream, , data returns byte string.

and issue occurs because trying .find() on byte string passing in string argument. simple example show -

>>> b'hello'.find('hello') traceback (most recent call last):   file "<stdin>", line 1, in <module> typeerror: 'str' not support buffer interface 

you should .decode() data , example -

stdout = popen(callbackquery, shell=true, stdout=pipe, universal_newlines=true).stdout output = stdout.read.decode('<encoding>') #the encoding output of other process returned, can utf-8, etc.