Question

我必须编写一个函数file_stats，该函数以文件名作为参数，并返回一个包含三个数字的元组：行数，单词数和文件中的字符数

我写了一个代码，该代码未通过单元测试。但是输出很好。如何通过单元测试？

num_lines = 0
num_words = 0
num_chars = 0

def file_stats(filename):  

   global num_lines, num_words, num_chars  

   with open(filename, 'r') as file:
       for line in file:
           words = line.split()
           num_lines += 1
           num_words += len(words)
           num_chars += len(line)

   tuple1 = (num_lines, num_words, num_chars)
   file.close()
   return tuple1

SampleFile.txt

LIET

Now, by Saint Peter's Church and Peter too,
He shall not make me there a joyful bride.
I wonder at this haste; that I must wed
Ere he, that should be husband, comes to woo.
I pray you, tell my lord and father, madam,
I will not marry yet; and, when I do, I swear,
It sh

预期产量-（9,58,304）

Answer 1

global num_lines, num_words, num_chars

您正在使用全局变量。如果单元测试工具重复调用您的函数，则这些变量将仅初始化一次，从而产生错误的结果。

改为将代码更改为此：

def file_stats(filename):  

   num_lines, num_words, num_chars = (0,0,0)

   with open(filename, 'r') as file:
       for line in file:
           words = line.split()
           num_lines += 1
           num_words += len(words)
           num_chars += len(line)

   return (num_lines, num_words, num_chars)

您不需要手动关闭文件，上下文管理器（with open(...) as file）会为您完成

功能未提供预期结果，单元测试失败

1 个答案: