import subprocess
import shlex
def RateSentiment(sentiString):
    #open a subprocess using shlex to get the command line string into the correct args list format
    #Modify the location of SentiStrength.jar and D:/SentiStrength_Data/ if necessary
    p = subprocess.Popen(shlex.split("java -jar D:/Downloads/SentiStrength.jar stdin sentidata D:/SentiStrength_Data/"),stdin=subprocess.PIPE,stdout=subprocess.PIPE,stderr=subprocess.PIPE)
    #communicate via stdin the string to be rated. Note that all spaces are replaced with +
    #Can't send string in Python 3, must send bytes
    b = bytes(sentiString.replace(" ","+"), 'utf-8')
    stdout_byte, stderr_text = p.communicate(b)
    #convert from byte
    stdout_text = stdout_byte.decode("utf-8") 
    #replace the tab with a space between the positive and negative ratings. e.g. 1    -5 -> 1 -5
    stdout_text = stdout_text.rstrip().replace("\t"," ")
    return stdout_text + " " + sentiString
#An example to illustrate calling the process.
print(RateSentiment("lovely day"))

#The above is OK for one text but inefficient to repeatedly call for many texts. Try instead: 
#  either modify the above to submit a file
#  or modify the above to send multiple lines through multiple calls of p.communicate(b)