python - File position and word splitter -

i have program that

• takes text file several sentences
• asks user if want compress/decompress file.
• if compress chosen, sentence have unique words , positions of these words needed recreate sentence again.
• if decompress chosen, compressed text file need found , using position list given , unique words - decompressed - several sentences in files need on separate lines.

here code have managed create. subroutine , it's rather faulty.

uniquewords = [] positions = [] file =   def valchoice():     choice = (" ")     while choice not in ["compress", "decompress"]:         choice = input("choose compress or decompress").lower()         if choice not in ["compress", "decompress"]:             print("please input compress or decompress")     finalchoice = valchoice()   if finalchoice = ("compress"):     print("this confused..")   elif finalchoice = ("decompress"):     print("this confused..") 

what wrong code? how can fix it?

with caveat above, i'll take shot @ think you're asking.

to compress file, iterate through input words. store each word reference in dictionary: word key, , position value. if word in dictionary, add new position reference existing list of references.

decompression works in reverse: make sequence of positions , words. sort sequence ascending order. concatenate words make original text.

is level of need right now?