如何在Python中的assert语句中使用小于和等于

Question

当我运行以下命令时：

growthRates = [3, 4, 5, 0, 3]
for each in growthRates:
    print each
    assert growthRates >= 0, 'Growth Rate is not between 0 and 100'
    assert growthRates <= 100, 'Growth Rate is not between 0 and 100'

我得到：

3
Traceback (most recent call last):
  File "ps4.py", line 132, in <module>
    testNestEggVariable()
  File "ps4.py", line 126, in testNestEggVariable
    savingsRecord = nestEggVariable(salary, save, growthRates)
  File "ps4.py", line 106, in nestEggVariable
    assert growthRates <= 100, 'Growth Rate is not between 0 and 100'
AssertionError: Growth Rate is not between 0 and 100

这是为什么？

Answer 1

不要

assert each >= 0, 'Growth Rate is not between 0 and 100'

：

assert growthRates >= 0, 'Growth Rate is not between 0 and 100'

Answer 2

assert 0 <= each <= 100, 'Growth Rate %i is not between 0 and 100.' % each

那么你的断言当然不会失败，但现在的增长率> 100，因为 GrowthRates 是列表，0 是整数，并且 'list'>'integer'。

Answer 3

断言（每个 >= 0）
不是 断言 (growthRates >= 0) :-)

Answer 4

您还可以使用：

growthRates = [0, 10, 100, -1]
assert all(0<=each<=100 for each in growthRates), 'growthRate is not between 0 and 100'

Traceback (most recent call last):
File "any.py", line 2, in <module>
assert all([0<=each<=100 for each in growthRates]), 'growthRate is not between 0 and 100'
AssertionError: growthRate is not between 0 and 100

Answer 5

测试每个而不是列表的增长率。

您还可以使用：

growthRates = [3, 4, 5, 0, 3]
testRange = range(0,100)
for each in growthRates:
    print each
    assert each in testRange, 'Growth Rate is not between 0 and 100'