回答此问题可获得 20 贡献值,回答如果被采纳可获得 50 分。
<pre><code>def double_preceding(values):
'''(list of ints)->None
Update each value in a list with twice
the preceding value, and the first item
with 0.
For example, if x has the value
[1,2,3,4,5], after calling the
double_preceding with argument x,
x would have the value[0,2,4,6,8]
>>>double_preceding(2,3,4,5,6)
[0,4,6,8,10]
>>>double_preceding(3,1,8,.5,10)
[0,6,2,16,1]
'''
if values != []:
temp = values[0]
values[0] = 0
for i in range(0, len(values)):
double = 2 * temp
temp = values[i]
values[i] = double
return #None
</code></pre>
<p>我做错什么了?我看不出有什么问题,我已经试着解决它一个小时了。在</p>
<p>我修正了密码:</p>
^{pr2}$