There are a variety of different ways to write a for loop in python. See below for different options. If you have any other suggestions please feel to add a comment.
Loop through a list one record at a time.
for rec in data: #Do Something
Loop through a range of numbers up to 100.
for i in range(100) #Do Something
Enumerate a list getting the index and value.
for idx, value in enumerate(data): #Do Something
Inline for loop.
d = [ x for x in data]
Inline for loop with an if condition.
d = [ x for x in data if x==1]