Behaviour of list comprehensions

[arsh.py at gmail.com]

I am having some understandable behaviour from one of my function name week_graph_data() which call two functions those return a big tuple of tuples, But in function week_graph_data() line no. 30 does not work(returns no result in graph or error). 

I have check both functions are called in week_graph_data() individually and those run perfectly. (returning tuple of tuples)

here is my code: pastebin.com/ck1uNu0U