python对列表中的元素进行去重操作

"""

有列表:["a","a","a","b","b","c","d","d","f"],

要求去除重复的列表数据,达到效果["a","b","c","d","f"]

"""

# 方法一：利用集合去重，不推荐，因为顺序会乱

list1 = ["a","a","a","b","b","c","d","d","f"]

list1 = list(set(list1)) # 先将list1转化为set集合去重，再将集合转化为列表

print(list1)

# 方法二：定义临时空列表，遍历原始列表，保存不重复的元素，最后打印临时列表。

list2 = ["a","a","a","b","b","c","d","d","f"]

temp_list = []    # 定义一个临时空列表，用于保存临时数据。

for i in list2:   # 遍历原列表，判断如果元素不在临时列表，就追加进去，如果在，就不加。

    if i not in temp_list:

        temp_list.append(i)

print(temp_list)

# 方法三：双重循环，外层循环遍历列表，内存循环控制删除重复元素的次数。如果元素个数统计大于1，则执行删除。

list3 = ["a","a","a","b","b","c","d","d","f"]

list3.reverse()  # 先反转列表，从后往前删

for i in list3:    # 外层循环控制每次需要判定的元素

    for _ in range(list3.count(i)):    # 内层循环控制每次执行删除元素的次数，循环多次就彻底删除。

        if list3.count(i) > 1:

            list3.remove(i)    # 如果该元素个数大于1，则执行删除操作

list3.reverse()      # 最后再反转列表，保证第一次出现的元素顺位保留下来

print(list3)