python开发_shelve_完整版_博主推荐

'''
    python中的shelve模块，可以提供一些简单的数据操作
    他和python中的dbm很相似。

    区别如下：
    都是以键值对的形式保存数据，不过在shelve模块中，
    key必须为字符串，而值可以是python所支持的数据
    类型。在dbm模块中，键值对都必须为字符串类型。

    sh['a'] = 'a'
    sh['c'] = [11, 234, 'a']
    sh['t'] = ('1', '2', '3')
    sh['d'] = {'a':'2', 'name':'Hongte' }
    sh['b'] = 'b'
    sh['i'] = 23

    我们可以获取一个shelve对象
    sh = shelve.open('c:\\test\\hongten.dat', 'c')

    删除shelve对象中的某个键值对
    del sh['d']

    遍历所有数据
    for item in sh.items():
        print('键[{}] = 值[{}]'.format(item[0], sh[item[0]]))

    获取某个键值对
    print(sh['a'])

    关闭shelve对象:
    sh.close()

    ####################################################
    ####        API中强调
    Do not rely on the shelf being closed automatically;
    always call close() explicitly when you don’t need
    it any more, or use a with statement with
    contextlib.closing().
    ####################################################

'''

下面是我做的demo，在demo中我做了比较详细的注释和说明，详情如下：

运行效果：

SHOW_LOG = False

Python 3.3.2 (v3.3.2:d047928ae3f6, May 16 2013, 00:03:43) [MSC v.1600 32 bit (Intel)] on win32
Type "copyright", "credits" or "license()" for more information.
>>> ================================ RESTART ================================
>>>
SHOW_LOG : False
删除所有数据...
保存数据...
##################################################
遍历所有数据...
数据[gender] = [M]
数据[phone] = [('13423****62', '18998****62')]
数据[age] = [22]
数据[name] = [Hongten]
数据[address] = [{'hometown': 'Shuifu,Yunnan', 'nowadd': 'Guangzhou,Guangdong'}]
##################################################
更新数据...
##################################################
遍历所有数据...
数据[gender] = [M]
数据[phone] = [('13423****62', '18998****62', '020-90909090')]
数据[name] = [Hongten]
数据[hoby] = [('篮球', '羽毛球', '乒乓球', '游泳')]
数据[age] = [23]
数据[address] = [{'hometown': 'Shuifu,Yunnan', 'nowadd': 'Guangzhou,Guangdong'}]
##################################################
获取某个数据...
获取[address]的值：{'hometown': 'Shuifu,Yunnan', 'nowadd': 'Guangzhou,Guangdong'}
##################################################
删除某个数据...
##################################################
遍历所有数据...
数据[gender] = [M]
数据[phone] = [('13423****62', '18998****62', '020-90909090')]
数据[age] = [23]
数据[name] = [Hongten]
数据[address] = [{'hometown': 'Shuifu,Yunnan', 'nowadd': 'Guangzhou,Guangdong'}]
##################################################
删除所有数据...
##################################################
遍历所有数据...
>>> 

SHOW_LOG = True

Python 3.3.2 (v3.3.2:d047928ae3f6, May 16 2013, 00:03:43) [MSC v.1600 32 bit (Intel)] on win32
Type "copyright", "credits" or "license()" for more information.
>>> ================================ RESTART ================================
>>>
SHOW_LOG : True
删除所有数据...
保存数据...
保存数据[age] = [22]
保存数据[gender] = [M]
保存数据[address] = [{'hometown': 'Shuifu,Yunnan', 'nowadd': 'Guangzhou,Guangdong'}]
保存数据[phone] = [('13423****62', '18998****62')]
保存数据[name] = [Hongten]
##################################################
遍历所有数据...
数据[age] = [22]
数据[name] = [Hongten]
数据[gender] = [M]
数据[address] = [{'hometown': 'Shuifu,Yunnan', 'nowadd': 'Guangzhou,Guangdong'}]
数据[phone] = [('13423****62', '18998****62')]
##################################################
更新数据...
更新数据[name] = [Hongten]
更新数据[hoby] = [('篮球', '羽毛球', '乒乓球', '游泳')]
更新数据[phone] = [('13423****62', '18998****62', '020-90909090')]
更新数据[age] = [23]
##################################################
遍历所有数据...
数据[age] = [23]
数据[gender] = [M]
数据[address] = [{'hometown': 'Shuifu,Yunnan', 'nowadd': 'Guangzhou,Guangdong'}]
数据[hoby] = [('篮球', '羽毛球', '乒乓球', '游泳')]
数据[phone] = [('13423****62', '18998****62', '020-90909090')]
数据[name] = [Hongten]
##################################################
获取某个数据...
获取[address]的值：{'hometown': 'Shuifu,Yunnan', 'nowadd': 'Guangzhou,Guangdong'}
##################################################
删除某个数据...
删除[hoby]的数据
##################################################
遍历所有数据...
数据[age] = [23]
数据[name] = [Hongten]
数据[gender] = [M]
数据[address] = [{'hometown': 'Shuifu,Yunnan', 'nowadd': 'Guangzhou,Guangdong'}]
数据[phone] = [('13423****62', '18998****62', '020-90909090')]
##################################################
删除所有数据...
删除数据[age] = [23]
删除数据[gender] = [M]
删除数据[address] = [{'hometown': 'Shuifu,Yunnan', 'nowadd': 'Guangzhou,Guangdong'}]
删除数据[phone] = [('13423****62', '18998****62', '020-90909090')]
删除数据[name] = [Hongten]
##################################################
遍历所有数据...
>>> 

=====================================================

代码部分：

=====================================================

 #python shelve

 #Author : Hongten
 #MailTo : hongtenzone@foxmail.com
 #QQ     : 648719819
 #Blog   : http://www.cnblogs.com/hongten
 #Create : 2013-08-09
 #Version: 1.0

 import shelve
 '''
     python中的shelve模块，可以提供一些简单的数据操作
     他和python中的dbm很相似。

     区别如下：
     都是以键值对的形式保存数据，不过在shelve模块中，
     key必须为字符串，而值可以是python所支持的数据
     类型。在dbm模块中，键值对都必须为字符串类型。

     sh['a'] = 'a'
     sh['c'] = [11, 234, 'a']
     sh['t'] = ('1', '2', '3')
     sh['d'] = {'a':'2', 'name':'Hongte' }
     sh['b'] = 'b'
     sh['i'] = 23

     我们可以获取一个shelve对象
     sh = shelve.open('c:\\test\\hongten.dat', 'c')

     删除shelve对象中的某个键值对
     del sh['d']

     遍历所有数据
     for item in sh.items():
         print('键[{}] = 值[{}]'.format(item[0], sh[item[0]]))

     获取某个键值对
     print(sh['a'])

     关闭shelve对象:
     sh.close()

     ####################################################
     ####        API中强调
     Do not rely on the shelf being closed automatically;
     always call close() explicitly when you don’t need
     it any more, or use a with statement with
     contextlib.closing().
     ####################################################

 '''
 #global var
 #是否显示日志信息
 SHOW_LOG = True

 def get_shelve():
     '''open -- file may get suffix added by low-level library'''
     return shelve.open('c:\\test\\hongten.dat', 'c')

 def save(sh):
     '''保存数据'''
     if sh is not None:
         sh['name'] = 'Hongten'
         sh['gender'] = 'M'
         sh['address'] = {'hometown' : 'Shuifu,Yunnan', 'nowadd' : 'Guangzhou,Guangdong'}
         sh['phone'] = ('13423****62', '18998****62')
         sh['age'] = 22
         if SHOW_LOG:
             for item in sh.items():
                 print('保存数据[{}] = [{}]'.format(item[0], sh[item[0]]))
         sh.close()
     else:
         print('the shelve object is None!')

 def update(sh):
     '''更新数据'''
     if sh is not None:
         sh['name'] = 'Hongten'
         sh['hoby'] = ('篮球', '羽毛球', '乒乓球', '游泳')
         sh['phone'] = ('13423****62', '18998****62', '020-90909090')
         sh['age'] = 23
         if SHOW_LOG:
             keys = ('name', 'hoby', 'phone', 'age')
             for item in keys:
                 print('更新数据[{}] = [{}]'.format(item, sh[item]))
         sh.close()
     else:
         print('the shelve object is None!')

 def delete(sh, key):
     '''删除某个数据'''
     if sh is not None:
         if SHOW_LOG:
             print('删除[{}]的数据'.format(key))
         del sh[key]
         sh.close()
     else:
         print('the shelve object is None!')

 def deleteall(sh):
     '''删除所有数据'''
     if sh is not None:
         for item in sh.items():
             if SHOW_LOG:
                 print('删除数据[{}] = [{}]'.format(item[0], sh[item[0]]))
             del sh[item[0]]
         sh.close()
     else:
         print('the shelve object is None!')

 def fetchone(sh, key):
     '''获取某个数据'''
     if sh is not None:
         print('获取[{}]的值：{}'.format(key, sh[key]))
         sh.close()
     else:
         print('the shelve object is None!')

 def fetchall(sh):
     '''遍历所有数据'''
     if sh is not None:
         for item in sh.items():
             print('数据[{}] = [{}]'.format(item[0], sh[item[0]]))
         sh.close()
     else:
         print('the shelve object is None!')

 ###############################################################
 ###                测试           START
 ###############################################################
 def save_test():
     '''保存数据...'''
     print('保存数据...')
     sh = get_shelve()
     save(sh)

 def fetchall_test():
     '''遍历所有数据'''
     print('遍历所有数据...')
     sh = get_shelve()
     fetchall(sh)

 def fetchone_test():
     '''获取某个数据'''
     print('获取某个数据...')
     sh = get_shelve()
     key = 'address'
     fetchone(sh, key)

 def delete_test():
     '''删除某个数据'''
     print('删除某个数据...')
     sh = get_shelve()
     key = 'hoby'
     delete(sh, key)

 def update_test():
     '''更新数据...'''
     print('更新数据...')
     sh = get_shelve()
     update(sh)

 def deleteall_test():
     '''删除所有数据'''
     print('删除所有数据...')
     sh = get_shelve()
     deleteall(sh)

 ###############################################################
 ###                测试           END
 ###############################################################

 def init():
     global SHOW_LOG
     SHOW_LOG = True
     print('SHOW_LOG : {}'.format(SHOW_LOG))
     deleteall_test()
     save_test()

 def main():
     init()
     print('#' * 50)
     fetchall_test()
     print('#' * 50)
     update_test()
     print('#' * 50)
     fetchall_test()
     print('#' * 50)
     fetchone_test()
     print('#' * 50)
     delete_test()
     print('#' * 50)
     fetchall_test()
     print('#' * 50)
     deleteall_test()
     print('#' * 50)
     fetchall_test()

 if __name__ == '__main__':
     main()