Example bad file parsing function

bad_file_parsing.py

def serialise_file(document,format):
    
    if format =='txt':
        with open(document, 'r') as file:
            string = file.read().replace('\n', ' ')
        return string 
        
    elif format == 'docx'
        #docx parsing code here
        
    elif format == 'pdf':
        #pdf parsing code here
        
    else:
        raise ValueError(format)