adding numbers in a list

[Serafim]

If I follow the example

>>> def add_num_to_list(lst, num):
...     new_list = [lst[0]]
...     for i in lst[1:]:
...         new_list.append(i+num+new_list[-1])
...     return new_list
... 
>>> print(add_num_to_list([0,0,0,0], 25))
[0, 25, 50, 75]
>>> print(add_num_to_list([5,10], 25))
[5, 40]

Where the last printout is an answer to the question asked by @bowlofred

But if I follow the text description:

>>> def add_num_to_list(lst, num):
...     new_list = []
...     for i in lst:
...         new_list.append(i+num+(new_list[-1] if new_list else 0))
...     return new_list
... 
>>> print(add_num_to_list([0,0,0,0], 25))
[25, 50, 75, 100]
>>> print(add_num_to_list([5,10], 25))
[30, 65]
>>>