Do things with Python (1)

Posted: July 10th, 2008 | Author: mike | Filed under: Script Language |

Python到底有多简洁、高效？

 1 import glob
 2 import os
 3 
 4 files = glob.glob('/cygdrive/c/Users/Mike/Desktop/Data Export/cube_export_*.txt')
 5 for file in files:
 6     #get file path and file name     
 7     (filePath, fileName) = os.path.split(file)
 8     rfile = open(file, "r")
 9     wfile = open('%s\\%s%s' %(filePath, fileName, "_calculations.txt"), "w")
10 
11     #get the content needed in text and write to new filE    
12     for line in rfile:
13         if line.find("Statement:") > -1:
14             wfile.write(line.lstrip("Statement:").rstrip())
15             wfile.write(";\r\n")
16     wfile.close()
17     rfile.close()

上面的代码完成了以下工作：

  1. 遍历目录下文件（注意是支持用通配符筛选文件）
  2. 打开文件
  3. 读取每行，并且过滤内容
  4. 写入新文件

下面是操作数据库的实例，我把一个表中的几个字段拼接插入到另一个表中。这里只展现了Python在格式化字符串的灵活之处。

如果用list来做，效果可能更佳。但是通过两个列子，足以看到Python的魅力所在。

 1 import pymssql
 2 
 3 conn = pymssql.connect(host='CDCVM4505', user='sa', password='sysadm', database='es0617')
 4 cur  = conn.cursor()
 5 cur2 = conn.cursor()
 6 
 7 query = "SELECT MemberID, Comment_Id FROM [Cell_Comment_Key_Budget2008_V2_1] ORDER BY Comment_ID"
 8 cur.execute(query)
 9 for x in range(cur.rowcount/10):
10     new_key = ";".join(["%s" %mid for mid, cid in cur.fetchmany(10)])
11     query = "UPDATE [Cell_Comment_Budget2008_V2_1] SET Comment_Key = '%s' WHERE Comment_Id = %s" %(new_key, cid)
12     res = cur2.execute(query)
13 
14 conn.commit()
15 conn.close()
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