2011-06-20 46 views
4

我正在使用Python(pl/python,实际上)在一个非常大的文本对象中连续查找一系列正则表达式匹配。这工作正常!每个匹配是一个不同的结果,每个替换将是一个不同的结果,最终基于循环内的查询。使用python finditer,我怎样才能替换每个匹配的字符串?

目前,我很乐意用任何文字替换rx中的每一个匹配,这样我就能理解它是如何工作的。有人能给我一个替换匹配文本的明确例子吗?

match.group(1)似乎正确指示匹配的文本;这是做事情的方式吗?

plan3 = plpy.prepare("SELECT field1,field2 FROM sometable WHERE indexfield = $1", 
    [ "text" ]) 

rx = re.finditer('LEFT[A-Z,a-z,:]+RIGHT)', data) 

# above does find my n matches... 

# ------------------- THE LOOP ---------------------------------- 
for match in rx: 
# below does find the 6 match objects - good! 

# match.group does return the text 
plpy.notice("-- MATCH: ", match.group(1)) 

# must pull out a substring as the 'key' to an SQL find (a separate problem) 
# (not sure how to split based on the colon:) 
keyfield = (match.group(1).split, ':') 
plpy.notice("---------: ",kefield) 

try: 
rv = plpy.execute(plan3, [ keyfield ], 1) 

# --- REPLACE match.group(1) with results of query 
# at this point, would be happy to replace with ANY STRING to test... 
except: 
plpy.error(traceback.format_exc()) 

# ------------------- (END LOOP) ------------------------------ 

回答

6

您需要改为re.sub()

import re 

def repl(var): 
    return var.group().encode('rot13') 

print re.sub('[aeiou]', repl, 'yesterday') 

yrstrrdny

+0

伊格纳西奥 - OK,TKS这个 - 现在我想应用re.sub(),取得了一些成功。但是,我如何在匹配中搜索子字符串,以便抽出一些我需要的信息? – DrLou

+0

该函数将传递[match object](http://docs.python.org/library/re.html#match-objects) –

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