如何让水仙花数判断函数支持整数、数组、字符串多类型输入？

Hey Steve, let's expand your narcissistic number checker to handle integers, arrays, and string inputs smoothly! Here's a robust solution with step-by-step explanations:

First, a quick recap: a narcissistic number is a number equal to the sum of its own digits each raised to the power of the total number of digits. For example, 153 = 1³ + 5³ + 3³.

Full Implementation Code #

def is_narcissistic(input_data):
    # Step 1: Normalize input into a list of digits and capture original number
    digits = []
    original_num = None
    
    if isinstance(input_data, int):
        # Handle integer input
        original_num = input_data
        digits = [int(d) for d in str(input_data)]
    elif isinstance(input_data, str):
        # Handle string input (must be a valid numeric string)
        if not input_data.isdigit():
            return False  # Swap with `raise ValueError("Invalid numeric string")` for explicit errors
        original_num = int(input_data)
        digits = [int(d) for d in input_data]
    elif isinstance(input_data, list):
        # Handle array input (all elements must be single-digit integers)
        if not all(isinstance(d, int) and 0 <= d <= 9 for d in input_data):
            return False  # Swap with `raise ValueError("Array contains invalid digits")` for explicit errors
        original_num = int(''.join(map(str, input_data)))
        digits = input_data
    else:
        # Unsupported input type
        return False  # Swap with `raise TypeError("Unsupported input type")` for explicit errors
    
    # Step 2: Calculate sum of digits raised to the power of digit count
    digit_count = len(digits)
    sum_of_powers = sum(d ** digit_count for d in digits)
    
    # Step 3: Check if sum matches original number
    return sum_of_powers == original_num

Key Details #

• Input Normalization: We convert all valid input types into a consistent list of digits, while preserving the original number (as an integer) for comparison. This ensures the core logic works the same regardless of input type.
• Flexible Error Handling: The code returns False for invalid inputs by default, but you can swap those lines with raise statements if you want explicit error messages instead.
• Optimized Core Logic: Reuses the core idea from your original code, but removes unused variables (like the original total = []) and streamlines the digit-to-power calculation.

Test Cases to Verify #

Try these examples to confirm the function works as expected:

• is_narcissistic(153) → True (integer input)
• is_narcissistic("9474") → True (string input)
• is_narcissistic([1,6,3,4]) → True (array input)
• is_narcissistic("abc123") → False (non-numeric string)
• is_narcissistic([1, "5", 3]) → False (array with non-integer element)

内容的提问来源于stack exchange，提问作者Steve