Python内存使用情况？在内存中加载大型词典

hey all, I have a file on disk that's only 168MB. It's just a comma separated list of word,id the word can be 1-5 words long. There's 6.5 million lines. I created a dictionary in python to load this up into memory so I can search incoming text against that list of words. When python loads it up into memory it shows 1.3 GB's of RAM space used. Any idea why that is? hey all, I have a file on disk that's only 168M