超简单入门版词云图：
from wordcloud import WordCloud
import matplotlib.pyplot as plt
f = open(\'citu2.txt\',encoding = \'utf-8\').read()
wd = WordCloud(background_color =\'white\',width = 1000,height = 1000,
margin = 2).generate(f)
wd.to_file(\'b.jpg\')
效果图：