我的 python 列表程序由于某种原因无法运行

Question

a = []
s = 0
k = 0
for i in range(20):
    x = int(input())
    if x<0:
        s+=x
        k+=1
    a.append(x)
z = s/k
for i in range(20):
    l = (a[i])-z
    del a[i]
    a.append(l)
print(a)
input()

The task is: The values of a one-dimensional list of 20 elements are read from a standard data input stream. Convert the original list by subtracting from the value of each element of the list the arithmetic average of the negative elements of the list. The source data is integers ranging from -10^6 to 10^6.

Answer 1

This isn't the answer, but you've been dinged because your code isn't easily testable. Your description of the problem is vague and since your code is buggy we don't have a good idea what to expect of it. Its best to give sample input and sample output. And you should do it so that we can just copy/paste and run it.

Since this is something you should generally be doing with code anyway, here is an example of how to make your code testable. First, don't do anything at module level. Put the algorithm in a function

foo.py

import sys

def bar(input_sequence):
    a = []
    s = 0
    k = 0
    vals = iter(input_sequence)
    for i in range(20):
        x = next(vals)
        if x<0:
            s+=x
            k+=1
        a.append(x)
    z = s/k
    for i in range(20):
        l = (a[i])-z
        del a[i]
        a.append(l)

if __name__ == "__main__":
    a = foo(sys.stdin)
    print(a)

Now you can call foo() with canned input that you already know the result you want. Might as well put this in the python unittest framework so you can easily add and run tests as functionality of your program grows.

testfoo.py

import unittest
import foo

class TestFoo(unittest.TestCase):

    def test_bar_1():
        test_data = ['todo: fill in here']
        expected_result = ['todo: fill in here']
        result = foo.bar(test_data)
        self.assertEqual(expected_result, result)

if __name__ == "__main__":
    unitttest.main()

now you can go the command prompt and type

python testfoo.py

We can run this code and it tells us exactly what you expect the function to do. In a "test first" design, you'd write the testfoo.py before foo.py so that you'd have an easy way to validate the code as you write it.