Python：如何警告用户列表中的重复值

Question

我正在尝试编写一个程序，允许用户输入任意数量的整数。如您所见，他们将使用“lengthList =....”来决定这一点。我的目标是不仅要删除重复条目，还要通知用户重复项。我设法删除了重复项，但不知道如何通知用户他们的条目已被删除。例如“28 已经输入。从列表中删除。”

谢谢

result = "0"
intList = [] 
LengthList = int(input("Please enter the amount of numbers")        
while len(result) < LengthList:
 userNumber = input("Please input a number: ")
 intList.append(userNumber)
 removeDuplicate = set(intList)
 result = list(removeDuplicate)
print (result)

Answer 1

尝试使用列表来存储值并在添加数字之前测试输入的值是否在其中。 下面是我对这个问题的解决方案：

l = []
while True:
    userNumber = input("Please input a number: ")
    if userNumber not in l:
        userNumber = l.append(userNumber)
        print(l)
    else:
        print(f'{userNumber} already exist in the list, and your list is {l}')

输出：

Please input a number: 1
['1']
Please input a number: 1
1 already exist in the list, and your list is ['1']
Please input a number: 2
['1', '2']
Please input a number: 2
2 already exist in the list, and your list is ['1', '2']
Please input a number: 3

Answer 2

试试：

# Creating the results list
results = list()

# Casting the string input to int()
amount_of_numbers = int(input("Please enter the amount of numbers: "))

# While lenght of results is lower than the provided amount of numbers
while len(results) < amount_of_numbers:

    ## Casting the string input to int() since we want to store it as an integer and not as a string
    userNumber = int(input("Please input a number: "))

    ## If the input number is not already in results list
    if userNumber not in results:
        # Appending the input number to results list
        results.append(userNumber)
    else:
        # Printing a message saying that the number already exists in results list
        print ("{} has already been entered".format(userNumber))
# Printing results list
print (results)

输出：

➜  python numbers.py
Please enter the amount of numbers: 4
Please input a number: 1
Please input a number: 2
Please input a number: 3
Please input a number: 1
1 has already been entered
Please input a number: 2
2 has already been entered
Please input a number: 3
3 has already been entered
Please input a number: 4
[1, 2, 3, 4]