如何通过循环在isinstance函数中传递元组？代码问题求助

Let's walk through fixing your code step by step. There are a few key issues preventing your type validation from working correctly:

Key Issues in Your Code #

1. Incorrect isinstance Call: You're passing a single tuple (i) to isinstance, but it requires two arguments: the value to check and the expected type(s). You need to unpack each tuple in key_data into these two separate values.
2. KeyError Handling: Your except clause overwrites the err_path variable and doesn't clearly indicate which key is missing.
3. Potential Unhandled Missing Keys: Accessing payload["Device"] directly can raise a KeyError if "Device" isn't present in the payload.

Corrected Code #

Here's the revised version with explanations:

def validate_record_schema():
    """Validate that the 0 or more Payload dicts in record use proper types"""
    try:
        for record in test1:  # Assuming `test1` is your list of target records
            for device_entry in record.get('Payload', []):
                payload = device_entry.get('Payload', None)
                if payload is None:
                    continue
                # Check if "Device" exists in payload before accessing it
                if "Device" not in payload:
                    print("Missing key: 'Device' in payload")
                    return False
                device = payload["Device"]
                
                # Define your value-type pairs for validation
                key_data = (
                    (device["ManualAdded"], bool),
                    (device["Location"], str)
                )
                
                for value, expected_type in key_data:
                    # Unpack each tuple and validate the type
                    if not isinstance(value, expected_type):
                        print(f"Invalid type for '{value}': expected {expected_type.__name__}")
                        return False
    except KeyError as e:
        print(f"Missing required key: {e}")
        return False
    return True

# Call the function and print the validation result
print(validate_record_schema())

What Changed? #

• Unpacking Tuples in the Loop: Instead of passing the entire tuple to isinstance, we unpack each entry into value and expected_type, then use these as the two required arguments for the type check.
• Explicit "Device" Check: Added a check to ensure "Device" exists in the payload before accessing it, with a clear error message to aid debugging.
• Improved KeyError Handling: Now captures the exact missing key from the exception and prints it, making it easier to identify where the schema breaks.
• Clear Error Messages: Added specific messages for type mismatches and missing keys, so you know exactly what's wrong without extra guesswork.

This code will now correctly loop through your type-check tuples and validate each value against its expected type.

内容的提问来源于stack exchange，提问作者nrs