Removing duplicate elements from a Python list containing unhashable elements while preserving order?
[
[('A', '1'), ('B', '2')],
[('A', '1'), ('B', '2')],
[('A', '4'), ('C', '5')]
]

[
[('A', '1'), ('B', '2')],
[('A', '4'), ('C', '5')]
]

sample = []
sample.append([('A', '1'), ('B', '2')])
sample.append([('A', '1'), ('B', '2')])
sample.append([('A', '4'), ('C', '5')])

from operator import itemgetter
from itertools import groupby, imap

def unique_justseen(iterable, key=None):
    "List unique elements, preserving order. Remember only the element just seen."
    # unique_justseen('AAAABBBCCDAABBB') --> A B C D A B
    # unique_justseen('ABBCcAD', str.lower) --> A B C A D
    return imap(next, imap(itemgetter(1), groupby(iterable, key)))

from bisect import bisect_left, insort

def dedup(seq):
    'Remove duplicates. Preserve order first seen.  Assume orderable, but not hashable elements'
    result = []
    seen = []
    for x in seq:
        i = bisect_left(seen, x)
        if i == len(seen) or seen[i] != x:
            seen.insert(i, x)
            result.append(x)
    return result

def unique(a):
    indices = sorted(range(len(a)), key=a.__getitem__)
    indices = set(next(it) for k, it in
                  itertools.groupby(indices, key=a.__getitem__))
    return [x for i, x in enumerate(a) if i in indices]

>>> a = ['F', 'J', 'B', 'F', 'V', 'A', 'E', 'U', 'B', 'U', 'Z', 'K']
>>> unique(a)
['F', 'J', 'B', 'V', 'A', 'E', 'U', 'Z', 'K']

seen = set()
output = []
for e in yourlist:
    t = tuple(e)
    if t in seen:
        continue
    else:
        seen.add(t)
        output.append(e)

# return output