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+--- Thread: removing duplicate numbers from a list (/thread-19134.html)
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RE: removing duplicate numbers from a list - ThomasL - Jun-15-2019
But creating a copy of the list makes the runtime even worse.
In addition to what i said above not only numbers.count()
has to iterate over the whole list, so has numbers.remove()
as this method has to search for the element to be removed.
If n == len(numbers) worst runtime is O(n) + O(n)*2*O(n)
If n is big you really don´t want this to be.
RE: removing duplicate numbers from a list - perfringo - Jun-15-2019
If lists are huge (thus memory can be a problem) and one doesn't need list but stream on unique values in order of appearance then generator can be option:
def uniquify(lst):
seen = set()
for item in lst:
if item not in seen:
yield item
seen.add(item)
for num in uniquify(numbers):
# do_something
RE: removing duplicate numbers from a list - DeaD_EyE - Jun-16-2019
In this case the set grows and grows if the entropy is high.
At some point you need a database, which returns unique values.
But in the most cases beginners don't do this kind of tasks.