Issue #13491: Fix many errors in sqlite3 documentation

Initial patch by Johannes Vogel.

Doc/includes/sqlite3/text_factory.py

@@ -3,9 +3,6 @@ import sqlite3
 con = sqlite3.connect(":memory:")
 cur = con.cursor()
 
-# Create the table
-con.execute("create table person(lastname, firstname)")
-
 AUSTRIA = "\xd6sterreich"
 
 # by default, rows are returned as Unicode
@@ -14,30 +11,17 @@ row = cur.fetchone()
 assert row[0] == AUSTRIA
 
 # but we can make sqlite3 always return bytestrings ...
-con.text_factory = str
+con.text_factory = bytes
 cur.execute("select ?", (AUSTRIA,))
 row = cur.fetchone()
-assert type(row[0]) == str
+assert type(row[0]) is bytes
 # the bytestrings will be encoded in UTF-8, unless you stored garbage in the
 # database ...
 assert row[0] == AUSTRIA.encode("utf-8")
 
 # we can also implement a custom text_factory ...
-# here we implement one that will ignore Unicode characters that cannot be
-# decoded from UTF-8
-con.text_factory = lambda x: str(x, "utf-8", "ignore")
-cur.execute("select ?", ("this is latin1 and would normally create errors" +
-                         "\xe4\xf6\xfc".encode("latin1"),))
+# here we implement one that appends "foo" to all strings
+con.text_factory = lambda x: x.decode("utf-8") + "foo"
+cur.execute("select ?", ("bar",))
 row = cur.fetchone()
-assert type(row[0]) == str
-
-# sqlite3 offers a built-in optimized text_factory that will return bytestring
-# objects, if the data is in ASCII only, and otherwise return unicode objects
-con.text_factory = sqlite3.OptimizedUnicode
-cur.execute("select ?", (AUSTRIA,))
-row = cur.fetchone()
-assert type(row[0]) == str
-
-cur.execute("select ?", ("Germany",))
-row = cur.fetchone()
-assert type(row[0]) == str
+assert row[0] == "barfoo"