我们将绘制，（i）预定长度Vs使用matplotlib对所有不同语言的书籍的唯一单词数量。我们将导入pandas以创建一个pandas数据框架，它将书籍信息保存为列。我们将对这些列进行分类通过不同的类别，如“语言”，“作者”，“标题”，“长度”和“唯一”。要绘制沿x轴的书长和沿y轴的唯一字数，我们编码：

import os

import pandas as pd

book_dir = "./Books"

os.listdir(book_dir)

stats = pd.DataFrame(columns =("language", "author", "title", "length", "unique"))

# check >>>stats

title_num = 1

for language in os.listdir(book_dir):

for author in os.listdir(book_dir+"/"+language):

for title in os.listdir(book_dir+"/"+language+"/"+author):

inputfile = book_dir+"/"+language+"/"+author+"/"+title

print(inputfile)

text = read_book(inputfile)

(num_unique, counts) = word_stats(count_words_fast(text))

stats.loc[title_num]= language, author.capitalize(), title.replace(".txt", ""),

sum(counts), num_unique

title_num+= 1

import matplotlib.pyplot as plt

plt.plot(stats.length, stats.unique, "bo-")

plt.loglog(stats.length, stats.unique, "ro")

stats[stats.language =="English"] #to check information on english books

plt.figure(figsize =(10, 10))

subset = stats[stats.language =="English"]

plt.loglog(subset.length, subset.unique, "o", label ="English", color ="crimson")

subset = stats[stats.language =="French"]

plt.loglog(subset.length, subset.unique, "o", label ="French", color ="forestgreen")

subset = stats[stats.language =="German"]

plt.loglog(subset.length, subset.unique, "o", label ="German", color ="orange")

subset = stats[stats.language =="Portuguese"]

plt.loglog(subset.length, subset.unique, "o", label ="Portuguese", color ="blueviolet")

plt.legend()

plt.xlabel("Book Length")

plt.ylabel("Number of Unique words")

plt.savefig("fig.pdf")

plt.show()