import re
s = "Executing identify -format %k 'testcases/art/test_files/video_images/single-[snk1=640x480p59.9]-[src1=720x480i59.9].png'"
print( re.findall("^.+\'(.+.png)", s) )
print( re.findall("^.+'(.+.png)", s) )
aW1wb3J0IHJlCnMgPSAiRXhlY3V0aW5nIGlkZW50aWZ5IC1mb3JtYXQgJWsgJ3Rlc3RjYXNlcy9hcnQvdGVzdF9maWxlcy92aWRlb19pbWFnZXMvc2luZ2xlLVtzbmsxPTY0MHg0ODBwNTkuOV0tW3NyYzE9NzIweDQ4MGk1OS45XS5wbmcnIgpwcmludCggcmUuZmluZGFsbCgiXi4rXCcoLisucG5nKSIsIHMpICkKcHJpbnQoIHJlLmZpbmRhbGwoIl4uKycoLisucG5nKSIsIHMpICk=