Python breaking down list in loop based on total

Question

I have what I think is a fairly complicated problem to solve. For each item in a list I must get a total area. When the area of enough of those items meets a total area, those items must be split into a separate list. The process will then continue for the subsequent items in the list.

The code looks something like this, but does not work yet:

all_areas = [1,2,3,4,5,6,7,8,9]

def get_area(n):
  # in my actual code the function does more than just return n as it is.
  return n

for i in all_areas:
  total_area=0
  ids=[]
  while total_area < 20:
    area = get_area(i)
    total_area+=area
    ids.append(i)
  else:
    # pass along ids before resetting counters
    call_another_function(ids)
    total_area=0
    ids=[]

With 20 as the threshold and with the given parameters, I am intending the call_another_function will be called once with [1,2,3,4,5,6] and then another time with [7,8,9]. The loop will then finish. Some help with this problem would be appreciated.

I was also wondering if this would be a suitable circumstance to use yield and generators? These seem to be a useful capability of Python that I have not ever had to use before.

Answer 1

Here is a method. I'm not sure I see the value in using a generator here, but it may be helpful depending on the wider implementation:

all_areas = [1, 2, 3, 4, 5, 6, 7, 8, 9]
thr = 20
groups = []

while all_areas:
    total = 0
    cur = []
    while total < thr:
        if not all_areas:
            break
        x = all_areas.pop(0)
        total += x
        cur.append(x)
    groups.append(cur)

print(groups)

output:

[[1, 2, 3, 4, 5, 6], [7, 8, 9]]