为什么我不能让 Google 的 Python 测试工作？答案

【问题标题】：Why can't I get Google's Python test to work?为什么我不能让 Google 的 Python 测试工作？
【发布时间】：2014-07-20 02:33:02
【问题描述】：

我正在尝试使用 Google 的 Python 介绍 (https://developers.google.com/edu/python/exercises/basic) 来开始编程。

根据它给我的这些说明，我编写了以下代码：

# Given an int count of a number of donuts, return a string
# of the form 'Number of donuts: <count>', where <count> is the number
# passed in. However, if the count is 10 or more, then use the word 'many'
# instead of the actual count.
# So donuts(5) returns 'Number of donuts: 5'
# and donuts(23) returns 'Number of donuts: many'
def donuts(count):
  if count < 10:
    numberofdonuts = count
  else:
    numberofdonuts = 'many'
  print 'Number of donuts:', str(numberofdonuts)
  return

如果我只是告诉 Python 打印我编写的代码，它的输出看起来与指令所说的完全一样（例如：“甜甜圈数量：4”）。但是当它通过谷歌提供的测试模块时：

# Provided simple test() function used in main() to print
# what each function returns vs. what it's supposed to return.
def test(got, expected):
  if got == expected:
    prefix = ' OK '
  else:
    prefix = '  X '
  print '%s got: %s expected: %s' % (prefix, repr(got), repr(expected))


# Provided main() calls the above functions with interesting inputs,
# using test() to check if each result is correct or not.
def main():
  print 'donuts'
  # Each line calls donuts, compares its result to the expected for that call.
  test(donuts(4), 'Number of donuts: 4')
  test(donuts(9), 'Number of donuts: 9')
  test(donuts(10), 'Number of donuts: many')
  test(donuts(99), 'Number of donuts: many')

它不断返回一个“X”并说它得到“无”，如下所示：

donuts
Number of donuts: 4
  X  got: None expected: 'Number of donuts: 4'
Number of donuts: 9
  X  got: None expected: 'Number of donuts: 9'
Number of donuts: many
  X  got: None expected: 'Number of donuts: many'
Number of donuts: many
  X  got: None expected: 'Number of donuts: many'

我假设 Google 知道如何编写 Python去哪儿？

我想我在这里遗漏了一些非常基本的东西......

【问题讨论】：

标签： python string python-2.7

【解决方案1】：

您的函数打印，并且不返回值。

print 写入您的控制台或终端。调用者没有收到结果。

不使用print，而是返回字符串：

def donuts(count):
  if count < 10:
    numberofdonuts = count
  else:
    numberofdonuts = 'many'
  return 'Number of donuts: ' + str(numberofdonuts)

【讨论】：