extract_keywords

def extract_keywords(text, ignore_words = [],
                     min_word_length = 0,
                     ignore_numbers = True,
                     ignore_case = True):
    # Remove words with special characters
    filtered_text = ''.join(filter(lambda x:x in string.printable, text))
    
    # Create word tokens from the text string
    tokens = word_tokenize(filtered_text)
    
    # List of punctuations to be ignored 
    punctuations = ['(',')',';',':','[',']',',','.','--','-','#','!','*','"','%']
    
    # Get the stopwords list to be ignored
    stop_words = stopwords.words('english')

    # Convert ignore words from user to lower case
    ignore_words_lower = [x.lower() for x in ignore_words]
    
    # Combine all the words to be ignored
    all_ignored_words = punctuations + stop_words + ignore_words_lower
    
    # Get the keywords list
    keywords = [word for word in tokens \
                    if  word.lower() not in all_ignored_words
                    and len(word) >= min_word_length]    

    # Remove keywords with only digits
    if ignore_numbers:
        keywords = [keyword for keyword in keywords if not keyword.isdigit()]

    # Return all keywords in lower case if case is not of significance
    if ignore_case:
        keywords = [keyword.lower() for keyword in keywords]
    
    return keywords