Certain tweets measurement and count through twitter api.

I have a twitter account and i follow aproximately 150 other accounts. What i want to do is to make an application-script where i set a number of keywords and search for any tweet of my friends (tweets that i see posted in my home timeline-my home page)that include any of the words i set before. The script must count the tweets containing any of the keywords for a certain time frame. -for example 2 hours- There would be one measurement of all of the keywords and not one by one. The results would show how high would be the keyword topic for a certain period of time. For example we would have a graph showing the variation of the counted tweets in time. I tried to do this using php but i got nowhere. i suggested python. i do not know what should be best to use, the stream or any other twitter api with authentication...., i got pretty confused. The time i have for finishing the project is short about 2 weeks max.