python: remove element from a list (5)

python: remove element from a list (5)
Abstract: consider remove elements from a list

pop() is used for remove the last element from a list
>>> l
[1, 1, 2, 3, 4, 5, 6, 7, 8]
>>> l.pop()
8
>>> l
[1, 1, 2, 3, 4, 5, 6, 7]

remove() is used for removing a given element from a list. The below is remove the first element equal to 1.
>>> l.remove(1)
>>> l
[1, 2, 3, 4, 5, 6, 7]

>>> l
['0', '1', '2', '3', '4', '5', '6', '7', '8', '9']
>>> l.remove('4')
>>> l
['0', '1', '2', '3', '5', '6', '7', '8', '9']

del() can remove an element based on its index, or multiple elements.
>>> l
['0', '1', '2', '3', '5', '6', '7', '8', '9']
>>> del l[4]  #remove the fifth element
>>> l
['0', '1', '2', '3', '6', '7', '8', '9']

>>> l
['0', '1', '2', '3', '6', '7', '8', '9']
>>> del l[6:]  # delete all element from the sixth
>>> l
['0', '1', '2', '3', '6', '7']

Remove all elements meeting a given conditions from a list. The below is to remove all 'a'.
>>> l
['dasf', 'a', 'a34', 'bfthjjuy', 'z']
>>> [x for x in l if 'a' in x] #select all elements containing 'a'
['dasf', 'a', 'a34']
>>> [x for x in l if 'a' not in x] # remove all elements containing 'a'
['bfthjjuy', 'z']

filter() can also work well on removing elements:
>>> filter(lambda x: 'a' in x,l)
['dasf', 'a', 'a34']

Remove duplicates from a list.  The codes below give two approach.
class array:
    def __init__(self, array):
        self.list=array
        self.list_len=len(self.list)

#remove duplicates
    def remove_duplicate1(self):
        unique=[]
        duplicate=[]
        while len(self.list)>0:
            x=self.list.pop()
            if x in duplicate:
                pass
            else:
                if x in unique:
                    unique.remove(x)
                    duplicate.append(x)
                else:
                    unique.append(x)
        print unique
        print duplicate
        return unique

#remove duplicates
    def remove_duplicate2(self):
        x=0  #index of unique boundary
        y=self.list_len # index of duplicate boundary
        while x<y:
            A=self.list[x]
            #print A, self.list
            dup=[x]
            for i in range(x+1, y):
                if self.list[i]==A:
                    dup.append(i)
            #
            if len(dup)==1:
                x+=1
            else:
                #swithch index if there are duplicates
                for d in dup[::-1]:
                    y=y-1
                    self.list[d],self.list[y]=self.list[y],self.list[d]
            #print self.list, '\n'
        print 'unique:', self.list[:x]
        print 'duplicates:', self.list[y:]
        return self.list[:x]