lists = [[1, 2, 3], [4, 5, 6], [7, 8, 9]]
def format_list(items):
list_contents = ' '.join(str(it) for it in items) # convert contents to string too
return '[{}]'.format(list_contents) # wrap in brackets
formatted = format_list(format_list(l) for l in lists)
print formatted
bGlzdHMgPSBbWzEsIDIsIDNdLCBbNCwgNSwgNl0sIFs3LCA4LCA5XV0KCmRlZiBmb3JtYXRfbGlzdChpdGVtcyk6CiAgICBsaXN0X2NvbnRlbnRzID0gJyAnLmpvaW4oc3RyKGl0KSBmb3IgaXQgaW4gaXRlbXMpICMgY29udmVydCBjb250ZW50cyB0byBzdHJpbmcgdG9vCiAgICByZXR1cm4gJ1t7fV0nLmZvcm1hdChsaXN0X2NvbnRlbnRzKSAjIHdyYXAgaW4gYnJhY2tldHMKCmZvcm1hdHRlZCA9IGZvcm1hdF9saXN0KGZvcm1hdF9saXN0KGwpIGZvciBsIGluIGxpc3RzKQoKcHJpbnQgZm9ybWF0dGVk