''' Purpose: introduce summing accumulation
'''

# get a list of numbers
reply   = input( 'Enter a list of numbers: ' )
slist   = reply.split()     # slist is a list of numeric strings

print()
print( 'slist =', slist )
print()

# convert numeric text into numbers one by one
nlist = []  # initialize holder to prepare for adding elements

# for each numeric string (s) in the list slist
for s in slist :
    nbr = int( s )          # cast the numeric string into the type int
    nlist.append( nbr )     # append the int version into the list accumulator nlist
    print( 'nlist =', nlist )

# don't modify a list that you're going through in a for loop inside that for loop
# it will go on forever and gives you errors
# here, we want a new list for the list of numbers instead of modifying slist directly
# also it makes more sense if we have a new list because we use the two lists for different
# purposes

# by accumulation get the sum of the numbers
total = 0       # accumulator for a summation problem always starts with 0

# for each number
# (we named it number - doesn't matter what you name it)
# in our list of numbers nlist
for number in nlist :
    total = total + number         # add to our running total

# you can reuse loop variable! might mean different things between different for loops
# so use different variables for each for loop

# print summation
print( "sum(", nlist, "):", total )

# accumulator for a product problem always starts with 1 NOT 0!!!
# x * 0 = 0 always