Copy a file to s3.

def __put_key(self, local_file, target_file, acl='public-read', del_after_upload=False, overwrite=True, source="filename"):
        """Copy a file to s3."""
        action_word = "moving" if del_after_upload else "copying"

        try:
            self.k.key = target_file  # setting the path (key) of file in the container

            if source == "filename":
                # grabs the contents from local_file address. Note that it loads the whole file into memory
                self.k.set_contents_from_filename(local_file, self.AWS_HEADERS)
            elif source == "fileobj":
                self.k.set_contents_from_file(local_file, self.AWS_HEADERS)
            elif source == "string":
                self.k.set_contents_from_string(local_file, self.AWS_HEADERS)
            else:
                raise Exception("%s is not implemented as a source." % source)
            self.k.set_acl(acl)  # setting the file permissions
            self.k.close()  # not sure if it is needed. Somewhere I read it is recommended.

            self.printv("%s %s to %s" % (action_word, local_file, target_file))
            # if it is supposed to delete the local file after uploading
            if del_after_upload and source == "filename":
                try:
                    os.remove(local_file)
                except:
                    logger.error("Unable to delete the file: ", local_file, exc_info=True)

            return True

        except:
            logger.error("Error in writing to %s", target_file, exc_info=True)
            return False