code: def add_keyword_from_file(self, keyword_file, encoding="utf-8"):
          
          if not os.path.isfile(keyword_file):
              raise IOError("Invalid file path {}".format(keyword_file))
          with io.open(keyword_file, encoding=encoding) as f:
              for line in f:
                  if '=>' in line:
                      keyword, clean_name = line.split('=>')
                      self.add_keyword(keyword, clean_name.strip())
                  else:
                      keyword = line.strip()
                      self.add_keyword(keyword)
docs: To add keywords from a file
  
          Args:
              keyword_file : path to keywords file
              encoding : specify the encoding of the file
  
          Examples:
              keywords file format can be like:
  
              >>> # Option 1: keywords.txt content
              >>> # java_2e=>java
              >>> # java programing=>java
              >>> # product management=>product management
              >>> # product management techniques=>product management
  
              >>> # Option 2: keywords.txt content
              >>> # java
              >>> # python
              >>> # c++
  
              >>> keyword_processor.add_keyword_from_file('keywords.txt')
  
          Raises:
              IOError: If `keyword_file` path is not valid