How can I create multiple instances of a class and pass in values without having to do it manually?

Let's say we have a class called A

class A:
    def __init__(self, a, b, c):
        self.a = a
        self.b = b
        self.c = c

I want to take multiple inputs and pass them as arguments to the class

a = input()
b = input()
c = input()
d = input()
e = input()
f = input()
g = input()
h = input()
i = input()

ins1 = A(a, b, c)
ins2 = A(d, e, f)
ins3 = A(g, h, i)

How can I create these instances without having to type them like this?

I tried using a for loop but I couldn't figure out how I can make it work.

If you don't need the variables a–i for anything else than creating the instances of A and can use a list (say ins) instead of individual variables ins1, ins2, ins3, you can create the instances in a loop:

ins = [
    A(input(), input(), input())
    for _ in range(3)
]

You have 2 constants. One is the number of classes you want to construct and the other is the number of parameters that the class constructor requires (inputs).

# define the constants
NINPUTS = 3
NCLASSES = 3

# define the class
class A:
    def __init__(self, *params: str) -> None:
        assert len(params) == NINPUTS
        self._a, self._b, self._c = params
    def __str__(self) -> str:
        return f'a={self._a}, b={self._b}, c={self._c}'

# convenience function for acquiring a number of inputs (as strings)
def get_inputs(n: int) -> list[str]:
    return [input() for _ in range(n)]

# list comprehension to construct a list of classes
classes = [A(*get_inputs(NINPUTS)) for _ in range(NCLASSES)]

# print the list
print(*classes, sep='\n')