Python 过滤a文件中每一行内容,保存到b文件中

#coding=utf-8
print 1
#初始化文件crash_log.log
with open('e:/1/crash_log.log','w')as f:
    f.close()
def fw(self):
    print
    with open('e:/1/monkey_log.txt','r')as f1 , open('e:/1/crash_log.log','a+') as f2:
　　　　#设置循环读取每一行,判断过滤
        while True:
            line=f1.readline()
            if '// Monkey finished' in line:
                break
                f2.close()
            elif '// CRASH:' in line :
                f2.write(line+ '\n')
            elif '// Short Msg:' in line:
                f2.write(line+ '\n')
            elif '// Long Msg:' in line:
                f2.write(line+ '\n'+'\n'+'\n')

            #else:
                #continue
if __name__ == "__main__":
    fw()