items = ['one', 'two', 'three', 'four', 'five', 'six', 'seven', 'eight', 'nine', 'ten', 'eleven', 'twelve', 'tree']
count = 4
mustContain = ["e", "i"] # all of these characters at least once
mustNotContain = ["n", "o"] # none of those chars
hits = [
item for item in items if
len(item) == count and
all([c in item for c in mustContain]) and
all([c not in item for c in mustNotContain])
]
print(hits)
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