python實現根據指定字符截取對應的行的內容

工作中遇到的，在一個.c文件中有很多函數，這個.c是自動生成的，需要將所有的函數通過extern放到.h中，每個函數都是UINT32 O_開頭，通過正則表達式進行字符匹配以及通過linecache來截取特定行，代碼如下：

#! /usr/bin/env python
# encoding:utf-8
# ! /usr/bin/env python
# encoding:utf-8
import re
import linecache
infile = 'D:\infile.txt'
outfile = 'D:\outfile.txt'
lineNumber = 1
with open(infile,'r') as f:
	number = []
	for line in f.readlines():
		m = re.findall(r"UINT32 O_\w+",line)  #匹配含有字符'UINT32 O_'的行
		if m:
			number.append(lineNumber)
		n = re.findall(r"OUT \w+",line) #假設只有一個OUT
		if n:
			number.append(lineNumber)
		lineNumber += 1
	with open(outfile, 'w+') as f_w:
		for j in range(len(number)):
			if j%2 == 0:
				start = number[j]
				end = number[j+1]
				destlines = linecache.getlines(file)[start-1:end] #截取start-end行的字符，不包括start-1,但包含end行
				f_w.write('extern ')
				for i in range(len(destlines)):
					if i != len(destlines)-1:
						f_w.write(destlines[i])
					else:
						f_w.write(destlines[i].replace('\n',';\n'))
				f_w.write('\n')
	

輸入：

UINT32 O_FUNC1(UINT32 uwA,
IN UINT32 uwB,
IN UINT32* puwC,
IN UINT32* puwD,
OUT UINT32* puwE)
{
   //
}

　　輸出：

extern UINT32 O_FUNC1(UINT32 uwA,
IN UINT32 uwB,
IN UINT32* puwC,
IN UINT32* puwD,
OUT UINT32* puwE);