postgresql可以使用psycopg2模块与python集成。sycopg2是用于python编程语言的postgresql数据库适配器。 psycopg2是非常小，快速，稳定的。 您不需要单独安装此模块，因为默认情况下它会随着python 2.5.x版本一起发布。 如果还没有在您的机器上安装它，那么可以使用yum命令安装它，如下所示：
$yum install python-psycopg2
要使用psycopg2模块，必须首先创建一个表示数据库的connection对象，然后可以选择创建可以帮助您执行所有sql语句的游标对象。
以下python代码显示了如何连接到现有的数据库。 如果数据库不存在，那么它将自动创建，最后将返回一个数据库对象。
#!/usr/bin/python
import psycopg2
conn = psycopg2.connect(database="testdb", user="postgres", password="pass123", host="127.0.0.1", port="5432")
print "opened database successfully"
在这里指定使用testdb作为数据库名称，如果数据库已成功打开连接，则会提供以下消息：
open database successfully
以下python程序将用于在先前创建的数据库(testdb)中创建一个表：
#!/usr/bin/python
import psycopg2
conn = psycopg2.connect(database="testdb", user="postgres", password="pass123", host="127.0.0.1", port="5432")
print "opened database successfully"
cur = conn.cursor()
cur.execute('''create table company
(id int primary key not null,
name text not null,
age int not null,
address char(50),
salary real);''')
print "table created successfully"
conn.commit()
conn.close()
当执行上述程序时，它将在数据库testdb中创建company表，并显示以下消息：
opened database successfully
table created successfully
以下python程序显示了如何在上述示例中创建的company表中创建记录：
#!/usr/bin/python
import psycopg2
conn = psycopg2.connect(database="testdb", user="postgres", password="pass123", host="127.0.0.1", port="5432")
print "opened database successfully"
cur = conn.cursor()
cur.execute("insert into company (id,name,age,address,salary) \
values (1, 'paul', 32, 'california', 20000.00 )");
cur.execute("insert into company (id,name,age,address,salary) \
values (2, 'allen', 25, 'texas', 15000.00 )");
cur.execute("insert into company (id,name,age,address,salary) \
values (3, 'teddy', 23, 'norway', 20000.00 )");
cur.execute("insert into company (id,name,age,address,salary) \
values (4, 'mark', 25, 'rich-mond ', 65000.00 )");
conn.commit()
print "records created successfully";
conn.close()
当执行上述程序时，它将在company表中创建/插入给定的记录，并显示以下两行：
opened database successfully
records created successfully
以下python程序显示了如何从上述示例中创建的company表中获取和显示记录：
#!/usr/bin/python
import psycopg2
conn = psycopg2.connect(database="testdb", user="postgres", password="pass123", host="127.0.0.1", port="5432")
print "opened database successfully"
cur = conn.cursor()
cur.execute("select id, name, address, salary from company")
rows = cur.fetchall()
for row in rows:
print "id = ", row[0]
print "name = ", row[1]
print "address = ", row[2]
print "salary = ", row[3], "\n"
print "operation done successfully";
conn.close()
执行上述程序时，会产生以下结果：
opened database successfully
id = 1
name = paul
address = california
salary = 20000.0
id = 2
name = allen
address = texas
salary = 15000.0
id = 3
name = teddy
address = norway
salary = 20000.0
id = 4
name = mark
address = rich-mond
salary = 65000.0
operation done successfully
以下python代码显示了如何使用update语句来更新任何记录，然后从company表中获取并显示更新的记录：
#!/usr/bin/python
import psycopg2
conn = psycopg2.connect(database="testdb", user="postgres", password="pass123", host="127.0.0.1", port="5432")
print "opened database successfully"
cur = conn.cursor()
cur.execute("update company set salary = 25000.00 where id=1")
conn.commit
print "total number of rows updated :", cur.rowcount
cur.execute("select id, name, address, salary from company")
rows = cur.fetchall()
for row in rows:
print "id = ", row[0]
print "name = ", row[1]
print "address = ", row[2]
print "salary = ", row[3], "\n"
print "operation done successfully";
conn.close()
执行上述程序时，会产生以下结果：
opened database successfully
total number of rows updated : 1
id = 1
name = paul
address = california
salary = 25000.0
id = 2
name = allen
address = texas
salary = 15000.0
id = 3
name = teddy
address = norway
salary = 20000.0
id = 4
name = mark
address = rich-mond
salary = 65000.0
operation done successfully
以下python代码显示了如何使用delete语句来删除记录，然后从company表中获取并显示剩余的记录：
#!/usr/bin/python
import psycopg2
conn = psycopg2.connect(database="testdb", user="postgres", password="pass123", host="127.0.0.1", port="5432")
print "opened database successfully"
cur = conn.cursor()
cur.execute("delete from company where id=2;")
conn.commit
print "total number of rows deleted :", cur.rowcount
cur.execute("select id, name, address, salary from company")
rows = cur.fetchall()
for row in rows:
print "id = ", row[0]
print "name = ", row[1]
print "address = ", row[2]
print "salary = ", row[3], "\n"
print "operation done successfully";
conn.close()
执行上述程序时，会产生以下结果：
opened database successfully
total number of rows deleted : 1
id = 1
name = paul
address = california
salary = 20000.0
id = 3
name = teddy
address = norway
salary = 20000.0
id = 4
name = mark
address = rich-mond
salary = 65000.0
operation done successfully
