JSON Parsing Troubleshooting

Common JSON Parsing Errors

1. JSONDecodeError: Expecting value

Cause

Receiving empty data or non-JSON format data

Solution:

try:
    data = json.loads(event["data"])
except json.JSONDecodeError as e:
    print(f"JSON parsing failed: {e}")
    print(f"Raw data: {repr(event['data'])}")
    return

2. JSONDecodeError: Unterminated string

Cause

JSON string is truncated or contains special characters

Solution: Check data integrity, handle special characters

3. JSONDecodeError: Extra data

Cause

Extra characters after JSON data

Solution: Clean data, remove extra characters

JSON Parsing Debugging Tips

1. Enable Verbose Logging

def debug_json_parse(json_str, context=""):
    print(f"[DEBUG] {context} Raw data: {repr(json_str)}")
    try:
        data = json.loads(json_str)
        print(f"[DEBUG] {context} Parsing successful: {data}")
        return data
    except json.JSONDecodeError as e:
        print(f"[ERROR] {context} Parsing failed: {e}")
        return None

2. Check Data Format

def validate_sse_data(data):
    if not isinstance(data, dict):
        print(f"[WARNING] Data is not dictionary format: {type(data)}")
        return False
    
    required_fields = ["type", "sequence_number"]
    for field in required_fields:
        if field not in data:
            print(f"[WARNING] Missing required field: {field}")
            return False
    
    return True

3. Handle Nested JSON

def parse_nested_json(data):
    # Check if there's a nested data field
    if "data" in data and isinstance(data["data"], str):
        try:
            nested_data = json.loads(data["data"])
            return nested_data
        except json.JSONDecodeError:
            pass
    return data