你如何限制 python 的 input() 函数的输入参数的数量？

Question

Let's say I have this:

maxNumOfArgs = int(input("enter length of list: "))

listOfNums = input("enter space separated list elements: ")

Nothing is stopping the user from entering more arguments than maxNumOfArgs . Is there a concise, pythonic way to limit the number of entered arguments in the input() call?

Answer 1

When you split the str returned by input() , you can limit the number of splits by passing a parameter maxsplit .

Example:

>>> test = input("enter data: ")
a b c d e f
>>> args = test.split(" ", maxsplit=3)
>>> args
['a', 'b', 'c', 'd e f']

Note that, in the worst case, the array returned by split will have 4 elements, since you limited it to 3 splits.

Answer 2

When you split the second input string, you can then strip off any arguments beyond the requested maximum length

# Get requested length
max_num_args = int(input("enter length of list: "))

# Get input string of comma-separated elements
all_inputs = input("enter space separated list elements: ")

# Split string by comma and only keep up to the maximum requested list length
input_values = all_inputs.split(',')[:max_num_args]