Question

What is Python’s equivalent of Perl’s DBI and how do I use it? More specifically, what is the Python equivalent of the following Perl code?

use DBI;

# connect to a MySQL database
my $dbh = DBI->connect("dbi:mysql:database=$database; host=localhost; port=3306", $user, $pass);

# select and read a few rows
my $sth = $dbh->prepare("SELECT id, name FROM table WHERE id <= ?;");
$sth->execute(321);
while (my @row = $sth->fetchrow_array) {
  my $id = $row[0];
  my $name = $row[1];
  print "$id. $name\n";
}

# write to the database
$sth = $dbh->prepare("INSERT INTO table (id, name) VALUES (?, ?);");
$sth->execute(123, "foo");

Answer 1

import MySQLdb.cursors

db = MySQLdb.connect(db=database, host=localhost,
                     port=3306, user=user, passwd=pass,
                     cursorclass=MySQLdb.cursors.DictCursor)
cur = db.cursor()

#this is not string interpolation, everything is quoted for you automatically
cur.execute("select id, name from table where id = %s", (321,))

for row in cur.fetchall():
    print "%s. %s" % (row['id'], row['name'])

cur.execute("insert into table (id, name) values (%s, %s)", (123, 'foo'))
db.commit() # required, because autocommit is off by default

Python database API use a common convention, that is pretty much the same across different databases (but not quite!). You can read the MySQLdb documentation here.

There is also a more feature-rich interface to mysql, called oursql. It has real parametrization (not just glorified string interpolation), server-side cursors, data streaming and so on.