我需要阅读一些非常大的文本文件（100+ Mb），用正则表达式处理每一行并将数据存储到一个结构中。我的结构继承自 defaultdict，它有一个读取 self.file_name 文件的 read(self) 方法。
看看这个非常简单（但不是真实的）示例，我没有使用正则表达式，但我正在拆分行：
import multiprocessing
from collections import defaultdict
def SingleContainer():
return list()
class Container(defaultdict):
"""
this class store odd line in self["odd"] and even line in self["even"].
It is stupid, but it's only an example. In the real case the class
has additional methods that do computation on readen data.
"""
def __init__(self,file_name):
if type(file_name) != str:
raise AttributeError, "%s is not a string" % file_name
defaultdict.__init__(self,SingleContainer)
self.file_name = file_name
self.readen_lines = 0
def read(self):
f = open(self.file_name)
print "start reading file %s" % self.file_name
for line in f:
self.readen_lines += 1
values = line.split()
key = {0: "even", 1: "odd"}[self.readen_lines %2]
self[key].append(values)
print "readen %d lines from file %s" % (self.readen_lines, self.file_name)
def do(file_name):
container = Container(file_name)
container.read()
return container.items()
if __name__ == "__main__":
file_names = ["r1_200909.log", "r1_200910.log"]
pool = multiprocessing.Pool(len(file_names))
result = pool.map(do,file_names)
pool.close()
pool.join()
print "Finish"
最后，我需要将每个结果加入一个容器中。保持行的顺序很重要。返回值时我的方法太慢了。更好的解决方案？我在 Linux 上使用 python 2.6