Python 列表去重去除空字符的例子

# x = ['c b a',"e d f"]# y = []# for i in x:# for ii in i:# # print(ii)# if ii == ' ':# pass# else:# y.append(ii)# print(y)

# list1 = ['122','2333','3444',' ','422',' ',' ','54',' ']# 第一种方法会导致最后一个' '没有被移除掉['122', '2333', '3444', '422', '54', ' ']# for x in list1:# if x == ' ':# list1.remove(' ')# print(list1)# 第二种方法：['122', '2333', '3444', '422', '54']# for x in list1:# if ' ' in list1:# list1.remove(' ')# print(list1)# 第三种方法：遍历空格的个数，然后逐个删除# for x in range(list1.count(' ')):# list1.remove(' ')# print(list1)# 第四种方法：用了while和for一样# while ' ' in list1:# list1.remove(' ')# print(list1)

# 第一种方法：使用replace,但是这种方法很笨，如果字符串中间有一万个空格怎么办，也要全部打出来吗# a = 'hello world'# b = a.replace(' ','')# print(b)# 第二种方法：# a = 'hello world'# a = list(a)# for x in a:# if ' ' in a:# a.remove(' ')# bb = ''.join(a)# print(bb)# a = 'hello wor ld'# # aa = a.split()# # print(aa)# # print(''.join(aa))# print(''.join(a.split()))# list1 = ['122','2333','3444',' ','422',' ',' ','54',' ']# for x in list1:# for i,j in enumerate(list1):# print(i,j)# if x == ' ':# list1.remove(' ')# print(list1)# print('***************************************')# print(list1)

# 方法一： 对列表进行怕羞，从头到尾进行比较，遇到重复的元素就删除，否则指针向右移动一位#方法1，逻辑复杂，临时变量保存值消耗内存，返回结果破坏了原列表顺序，效率最差# def deleteDuplicatedElement(l):# l.sort()# length = len(l)# firstItem = l[0]# for x in range(1,length-1):# # if x < length - 2:# # if l[x] == l[x+1]:# # l.remove(l[x])# # return l# currentItem = l[x]# if firstItem == currentItem:# l.remove(currentItem)# else:# firstItem = currentItem# return l# print(deleteDuplicatedElement(['d','d','1','2','1','4']))# def deleteDuplicatedElement(l):# l.sort()# length = len(l)# lastItem = l[length-1]# for x in range(length-2,-1,-1):# currentItem = l[x]# if lastItem == currentItem:# l.remove(currentItem)# else:# lastItem = currentItem# return l# print(deleteDuplicatedElement(['python','r','r','g','g','g','t','y','g','n']))# 方法二：设一临时列表保存结果，从头遍历原列表，如临时列表中没有当前元素则追加：#方法2，直接调用append方法原处修改列表，逻辑清晰，效率次之# def deleteDuplicatedElement(l):# ll = []# for x in l:# if x in ll:# continue# else:# ll.append(x)# return ll# print(deleteDuplicatedElement(['python','r','r','g','g','g','t','y','g','n']))# 方法三：利用Python中集合元素唯一性特点，将列表转换为集合，然后转换为列表输出即可#方法3，极度简洁，使用python原生方法效率最高，但列表原有顺序被打乱# def deleteDuplicatedElement(l):# return sorted(list(set(l)),key=l.index)# print(deleteDuplicatedElement(['python','r','r','g','g','g','t','y','g','n']))