has_duplicates; filter_duplicates

lab6-starter.py

def has_duplicates(xs):
    # Now with dictionaries:
    # create a dictionary "seen_already" that is empty.
    # loop over every element of xs
    #    if an element is in seen_already, return True
    #    else; add it to seen_already
    # if we haven't returned True by the end of the function, return False
    return False

assert(has_duplicates([1,2]) == False)
assert(has_duplicates([1,1,2]) == True)
assert(has_duplicates([1,2,1]) == True)
assert(has_duplicates(["a", "b", "b"]) == True)

def filter_duplicates(xs):
    output = []
    # Now, collect only those items you haven't seen_before into output
    return output

assert(filter_duplicates([1,2]) == [1,2])
assert(filter_duplicates([1,1,2]) == [1,2])
assert(filter_duplicates([1,2,1]) == [1,2])
assert(filter_duplicates(["a", "b", "b"]) == ["a", "b"])