Python: Remove values that are duplicated in the previous list inside a nested list

Example of a given nested list:

nList = [[2,5,99,99],[-3,8,1,2,10],[1, 7,100,10]]

Expectations: Remove values that are duplicated in the previous list.

Expected Output:

oList = [[2, 5, 99], [-3, 8, 1, 10], [7, 100]]

My Codes:

def RemoveDup(nList):
    lst = []
    for i in nList:
        for j in i:
            if j not in lst:
                lst.append(j)            
    return lst 

>>> print(RemoveDup([[2,5,99,99],[-3,8,1,2,10],[1, 7,100,10]]))
>>> [2, 5, 99, -3, 8, 1, 10, 7, 100]

I still couldn’t figure out how to make the output a nested list like the expected output, any help and advice are appreciated!

>Solution :

As there is no "previous" element to compare against the first element in the nested list then it must be dealt with as is.

This may achieve the real objective:

nList = [[2,5,99,99],[-3,8,1,2,10],[1, 7,100,10]]

output = [nList[0]]

for e in nList[1:]:
    t = []
    for x in e:
        if x not in output[-1]:
            t.append(x)
    output.append(t)

print(output)

Output:

[[2, 5, 99, 99], [-3, 8, 1, 10], [7, 100]]

If duplicates need to be removed from the first element in the list then:

nList = [[2,5,99,99],[-3,8,1,2,10],[1, 7,100,10]]

output = []

t = []

for e in nList[0]:
    if e not in t:
        t.append(e)
output.append(t)
for e in nList[1:]:
    t = []
    for x in e:
        if x not in output[-1]:
            t.append(x)
    output.append(t)

print(output)

Output:

[[2, 5, 99], [-3, 8, 1, 10], [7, 100]]

Note:

The temptation to use sets should be avoided as the order of the output list may not be as expected