试试这个：

try:
cursor = connection.cursor()
cursor.callproc("my_proc", json.dumps([fname, hash, json]))
cursor.close()
connection.commit()

finally：connection.close（）

这似乎对我很有效。如果你更新你的问题，提供更多细节，我们也许能发现你的问题

cursor = connection.cursor()
cursor.execute("""
               create or replace procedure my_proc (
                   p1 in varchar2,
                   p2 in varchar2,
                   p3 in clob,
                   p4 out varchar2
               ) as
               begin
                 p4 := p1 || p2 || p3;
               end;
               """)

hash = "abc"
fname = "def"
json = "ghi"
with connection.cursor() as cursor:
    myout = cursor.var(cx_Oracle.STRING)
    cursor.callproc("my_proc", [fname, hash, json, myout])
    print(myout.getvalue())

输出为：

defabcghi