How to run a long if statement in Jupyter notebook?

I'm trying to write a Jupyter notebook for the first time and I have a long if statement in the code. Jupyter notebook doesn't run my "if statement" when I put it into pieces. It run the code properly when the whole "if statement" is in one code cell but when I want to put mark down cells in the middle of the if statement to explain the code, it only creates one fits file instead of 4 files. It means the loop only runs for one time. Does anybody know how I can put mark down cells in the middle of if statement in Jupyter notebook?