infile = open("D:/test.txt", "r") #打开文件 outfile = open("D:/pp2.txt", "w") # 内容输出 for line in infile: #按行读文件，可避免文件过大，内存消耗 outfile.write(line.replace(‘ ‘, ‘ ‘))#first is old ,second is new infile.close() #文件关闭 outfile.close()
原文：http://www.cnblogs.com/rednodel/p/4565539.html