DBMS_DATAPUMPcan create SQL files from a schema so that these files can later be run to re-create the schema.
This is described in Oracle Note 1519981.1: How to Generate A SQL File Using The DBMS_DATAPUMP_API?. Unfortunately, the note does not explicitely state that the creation of such an sql file consists of two steps, first the schema has to be dumped ordinarly, then, the dumped file has to be turned into the desired SQL file.
Here are the steps to create such an SQL file.
First step: creating the dump file
Second step: turning the dump file into an SQL file
My question on dba.stackexchange.com