我如何检查一个列表是否有任何重复,并返回一个没有重复的新列表?


当前回答

Write a Python program to create a list of numbers by taking input from the user and then remove  the duplicates from the list. You can take input of non-zero numbers, with an appropriate  prompt, from the user until the user enters a zero to create the list assuming that the numbers  are non-zero.  
Sample Input: [10, 34, 18, 10, 12, 34, 18, 20, 25, 20]  
Output: [10, 34, 18, 12, 20, 25] 

 lst = []
print("ENTER ZERO NUMBER FOR EXIT !!!!!!!!!!!!")
print("ENTER LIST ELEMENTS  :: ")
while True:
    n = int(input())
    if n == 0 :
       print("!!!!!!!!!!! EXIT !!!!!!!!!!!!")
       break
    else :
        lst.append(n)
print("LIST ELEMENR ARE :: ",lst)
#dup = set()
uniq = []
for x in lst:
    if x not in uniq:
        uniq.append(x)
       # dup.add(x)
print("UNIQUE ELEMENTS IN LIST ARE :: ",uniq)

其他回答

有时你需要删除重复的项目,而不需要创建新的列表。例如,列表很大,或者将其作为影子副本保存

from collections import Counter
cntDict = Counter(t)
for item,cnt in cntDict.items():
    for _ in range(cnt-1):
        t.remove(item)

这里有一个例子,返回没有重复的列表,保持顺序。不需要任何外部导入。

def GetListWithoutRepetitions(loInput):
    # return list, consisting of elements of list/tuple loInput, without repetitions.
    # Example: GetListWithoutRepetitions([None,None,1,1,2,2,3,3,3])
    # Returns: [None, 1, 2, 3]

    if loInput==[]:
        return []

    loOutput = []

    if loInput[0] is None:
        oGroupElement=1
    else: # loInput[0]<>None
        oGroupElement=None

    for oElement in loInput:
        if oElement<>oGroupElement:
            loOutput.append(oElement)
            oGroupElement = oElement
    return loOutput

我没有看到非哈希值的答案,一行,nlog n,标准库,所以这是我的答案:

list(map(operator.itemgetter(0), itertools.groupby(sorted(items))))

或作为一个生成函数:

def unique(items: Iterable[T]) -> Iterable[T]:
    """For unhashable items (can't use set to unique) with a partial order"""
    yield from map(operator.itemgetter(0), itertools.groupby(sorted(items)))
Write a Python program to create a list of numbers by taking input from the user and then remove  the duplicates from the list. You can take input of non-zero numbers, with an appropriate  prompt, from the user until the user enters a zero to create the list assuming that the numbers  are non-zero.  
Sample Input: [10, 34, 18, 10, 12, 34, 18, 20, 25, 20]  
Output: [10, 34, 18, 12, 20, 25] 

 lst = []
print("ENTER ZERO NUMBER FOR EXIT !!!!!!!!!!!!")
print("ENTER LIST ELEMENTS  :: ")
while True:
    n = int(input())
    if n == 0 :
       print("!!!!!!!!!!! EXIT !!!!!!!!!!!!")
       break
    else :
        lst.append(n)
print("LIST ELEMENR ARE :: ",lst)
#dup = set()
uniq = []
for x in lst:
    if x not in uniq:
        uniq.append(x)
       # dup.add(x)
print("UNIQUE ELEMENTS IN LIST ARE :: ",uniq)

如果你想保持顺序,不使用任何外部模块,这里有一个简单的方法:

>>> t = [1, 9, 2, 3, 4, 5, 3, 6, 7, 5, 8, 9]
>>> list(dict.fromkeys(t))
[1, 9, 2, 3, 4, 5, 6, 7, 8]

注意:这种方法保留了出现的顺序,因此,如上所示,9将在1之后,因为它是第一次出现。然而,这和你做的结果是一样的

from collections import OrderedDict
ulist=list(OrderedDict.fromkeys(l))

但它更短,跑得更快。

这是因为每次fromkeys函数尝试创建一个新键时,如果值已经存在,它就会简单地覆盖它。然而,这不会影响字典,因为fromkeys创建的字典中所有键的值都为None,因此有效地消除了所有重复的值。