Python程序：从列表中删除重复项

编写一个Python程序，从给定的列表中删除所有重复项。集合不允许重复，因此我们可以将列表转换为集合，然后再将其转换回列表，这样就可以删除列表中的重复项。

dupList = [1, 2, 3, 2, 4, 8, 9, 1, 7, 6, 4, 5]
print("List Items = ", dupList)

uniqSet = set(dupList)
uniqList = list(uniqSet)
   
print("List Items after removing Duplicates = ", uniqList)

输出。

Python程序：使用for循环从列表中删除重复项

此Python程序允许输入列表大小和项目。for循环将遍历dupList中的项目。if语句结合not in运算符检查该值是否不存在于uniqList中。如果为True，则将该值追加到uniqList。

dupList = []

listNumber = int(input("Enter the Total List Items = "))
for i in range(1, listNumber + 1):
    listValue = int(input("Enter the %d List Item = " %i))
    dupList.append(listValue)

print("List Items = ", dupList)

uniqList = []

for val in dupList:
    if val not in uniqList:
        uniqList.append(val)
   
print("List Items after removing Duplicates = ", uniqList)

使用列表推导式

在此示例中，我们使用列表推导式来删除列表中的重复项。此代码与上面的示例相同，但我们使用了列表推导式的概念。

dupList = [1, 2, 5, 8, 1, 9, 11, 5, 22, 6, 2, 8, 14]

print("List Items = ", dupList)

uniqList = []
[uniqList.append(i) for i in dupList if i not in uniqList]

print("List Items after removing Duplicates = ", uniqList)

List Items =  [1, 2, 5, 8, 1, 9, 11, 5, 22, 6, 2, 8, 14]
List Items after removing Duplicates =  [1, 2, 5, 8, 9, 11, 22, 6, 14]

Python程序：使用collections.fromkeys删除列表重复项

在此示例中，我们从collections导入了OrderedDict，并使用fromkeys函数删除重复项。别忘了将结果转换为列表。

from collections import OrderedDict

dupList = [8, 1, 9, 2, 8, 4, 9, 11, 5, 22, 6, 4, 8]

print("List Items = ", dupList)

uniqList = OrderedDict.fromkeys(dupList)

print("List Items after removing Duplicates = ", list(uniqList))

使用OrderedDict from collections的输出。

使用unique函数删除列表重复项

numpy和pandas模块都有unique函数来删除重复项，因此我们使用了它们，并将结果转换为列表。为了转换结果，我们使用了tolist()函数。

import numpy as np
import pandas as pd

dupList = [1, 2, 2, 4, 1, 5, 6, 8, 6, 8, 9, 7, 4]
print("List Items = ", dupList)

uniqList = np.unique(dupList).tolist()
print("List Items after removing Duplicates = ", uniqList)

uniqList2 = pd.unique(dupList).tolist()
print("List Items after removing Duplicates = ", uniqList2)

numpy unique函数输出

List Items =  [1, 2, 2, 4, 1, 5, 6, 8, 6, 8, 9, 7, 4]
List Items after removing Duplicates =  [1, 2, 4, 5, 6, 7, 8, 9]
List Items after removing Duplicates =  [1, 2, 4, 5, 6, 8, 9, 7]

使用enumerate函数

此示例使用enumerate函数从列表中删除重复项。

from collections import OrderedDict

dupList = [1, 2, 3, 2, 4, 1, 5, 6, 5, 8, 7, 9, 8]

print("List Items = ", dupList)

uniqList = [val for x, val in enumerate(dupList) if val not in dupList[:x]]

print("List Items after removing Duplicates = ", uniqList)

enumerate示例的输出如下所示。

List Items =  [1, 2, 3, 2, 4, 1, 5, 6, 5, 8, 7, 9, 8]
List Items after removing Duplicates =  [1, 2, 3, 4, 5, 6, 8, 7, 9]