As @Barmar points out in their comments, this print issue is not related to pandas because the pandas.series.to_list() function returns a list object.
Also @Thornily is stating that this is related to your python console trying to conserve resources. The reason python uses summarization (...) is because printing an excessive number of lines is slow and will be very difficult to visual read through the output.
Finally, I think @BENY's comment can probably help provide insight into why you need to print this many. Like @Drakax has pointed out, you can use len(list_a) to verify the list has all 10,000 items in it.
I am assuming that the OP doesn't actually need to read all 10,000 records and that they likely want to know WHY they can't override the summarization (...). Unfortunately, I am still working on the WHY answer. I have tried changing the default preferences in my console and using numpy.set_printoptions(threshold=sys.maxsize) but I still get the elipsis. I will keep trying to answer the WHY question and will update this post if I find a good answer.
For now, IF you want a HOW answer, you can use the very slow method below. Keep in mind, I do not recommend printing the output to your console for the reasons stated above. But if you ABSOLUTELY have to print to your console you can do this:
for n in list_a:
    print(n)
or you can also convert using the list function to force the object to a python list and print multiple values on each console line:
list_a = list(list_a)
print(list_a)