Python-сообщество

 def fun (a,b):
    x=[]
    for c in a:
        if  c==b:
            x.append(c)
    return x
a = [1, 28, -1, 5, 2, 0, 33, 11, -2, 77, 4]
b = [98, -3, -2, -1, 55, 6, 7, 9]
print(fun(a,b))

 print(set(a) & set(b))

 print(set(a) & set(b))

 c = [element for element in a if element in b]

 for c in a:
        if not  c==b:
            x.append(c)
    return x

 c = [element for pos, element in enumerate(a) if element in b and pos == a.index(element)]