Here is a simple program to consume 20% of CPU usage in Python, using the `psutil` module:

```python

import os

import psutil

import time

p = psutil.Process(os.getpid())

target = 20 # target CPU usage in percentage

interval = 0.1 # interval to check and adjust CPU usage

sleeptime = 0.01 # initial sleep time between work cycles

while True:

? ? start = time.time()

? ? # do some work

? ? for i in range(100000):

? ? ? ? x = i ** 2

? ? end = time.time()

? ? worktime = end - start

? ? # check and adjust CPU usage

? ? usage = p.cpu_percent(interval=interval)

? ? if usage < target:

? ? ? ? sleeptime -= 0.001

? ? elif usage > target:

? ? ? ? sleeptime += 0.001

? ? # sleep for some time

? ? time.sleep(sleeptime)

```

這下就能工作了，也不是說這么做才對，并不是只有一個正確的做法。

展示了如何用bing來進(jìn)行修改，查詢方案，搜索方案，定位代碼，修改的順序，這樣就能編譯出一個可用的東西來。