Question

输入n个数字的通常方法是先询问n个数字，然后在不同的行中键入n个数字。

n = int(input())
for i in range(n):
    x = int(input())

我怎么要求n并仅在一行中输入n个数字。

类似这样的东西：

>> 4 1 2 3 4

Answer 1

我怎么要求n并仅在一行中输入n个数字。

如果从空格分隔的输入中可以明显看出您拥有多少个整数，则不需要不需要询问 n 。

但是，如果输入字符串格式是不可协商的，则可以通过序列解包来拆分：

n, *num_list = map(int, input().split())

例如，使用输入'4 1 2 3 4'，您将得到以下结果：

print(n, num_list)

4 [1, 2, 3, 4]

要了解以上逻辑：

input().split()将由空格输入的字符串分成一个列表。
map(int, X)返回int的可迭代，应用于X中的每个元素。
n, *num_list = map(...)迭代map对象，并分为第一个对象和其余对象。

更多习惯用法是自己计算n：

num_list = list(map(int, input().split()))
n = len(num_list)

例如，使用输入'1 2 3 4'，您将得到以下结果：

print(n, num_list)

4 [1, 2, 3, 4]

明确输入数字的唯一目的是进行检查。这可以通过assert语句来实现：

n, *num_list = map(int, input().split())

assert n == len(num_list), f'Check failed: {n} vs {len(num_list)} provided does not match'

Answer 2

space_separated_numbers = input()
num_list = [int(x) for x in space_separated_numbers.split()]

诀窍是立即将整个输入作为字符串，然后自己分割。

编辑：如果仅考虑获取第一个数字，则只需获取第一个值即可。

space_separated_numbers = input()
num = space_separated_numbers.split()[0]

Answer 3

也许您可以尝试将整个输入作为字符串处理。然后将它们转换为整数。在这种情况下，您也无需指定n的值。

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然后可以遍历列表来使用这些值。如果需要n的值，则只需获取列表的长度即可。

>>> x = [int(y) for y in input().split()]
1 2 3 4
>>> x
[1, 2, 3, 4]

如何要求n并仅在一行中输入n个数字

3 个答案: