iteration with for loops

initialize a variable to be accumulated, then in a for/while loop accumulate as you iterate through

for char in string:

#iterates through every character in string

for word in phrase:

#iterates through every word in sentence as separated by whitespace chars 

for num in range(0, 100):

#iterates through nums 0-99

for i in range(len(list)):

#iterated through indexes of list from 0 to len(list)

for elem in list:

#iterates through all elements of list

for i, elem in enumerate(list):

iterates through both i and elem in list

for a,b,c in zip(list_1, list_2, range(len(list_3))):

#iterates through parallel lists at same time