Syntax error in module 'lambda_function': name 'outputBucket' is used prior to global declaration (lambda_function.py, line 28)

[poojaalagar]

outputBucket = "attachment-desti-test" events bucket
outputPrefix = "csv/"

def lambda_handler(event, context):
bucket = event['Records'][0]['s3']['bucket']['name']
key = urllib.unquote_plus(event['Records'][0]['s3']['object']['key']).decode('utf8')

try:
    # Set outputBucket if required
    if not outputBucket:
        global outputBucket
        outputBucket = bucket