Strange error while trying to get URL of RPM package

[harish2704]

I am facing a strange error while trying to use python bindings of libzypp

the attached test program produces two different kind of outputs in two test cases as shown below
Output with bug

hari@harilocal:~/Downloads/squashfs-root/libzypp-bindings$ env CHECK_BUG=1 python2  libzypp_test.py | tail -n 3
http://download.opensuse.org/tumbleweed/repo/oss/��\B�U/plasma5-desktop-lang-5.13.0-1.1.noarch.rpm
http://download.opensuse.org/tumbleweed/repo/oss/p&�A�U/plasma5-session-5.13.0-1.1.noarch.rpm
http://download.opensuse.org/tumbleweed/repo/oss/е^B�U/plasma5-session-wayland-5.13.0-1.1.noarch.rpm

Output without bug

hari@harilocal:~/Downloads/squashfs-root/libzypp-bindings$ python2  libzypp_test.py | tail -n 3
http://download.opensuse.org/tumbleweed/repo/oss/./noarch/plasma5-desktop-lang-5.13.0-1.1.noarch.rpm
http://download.opensuse.org/tumbleweed/repo/oss/./noarch/plasma5-session-5.13.0-1.1.noarch.rpm
http://download.opensuse.org/tumbleweed/repo/oss/./noarch/plasma5-session-wayland-5.13.0-1.1.noarch.rpm
hari@harilocal:~/Downloads/squashfs-root/libzypp-bindings$ 

Piece of code which create this difference is given below

    if( 'CHECK_BUG' in os.environ ):
        itemUrl = str( item.lookupLocation().filename() )
    else:
        r=item.lookupLocation(); itemUrl = str( r.filename() )

Please see complete test program attached below

test_program_with_output.zip