Never resets list - python-3.x

Question

I am trying to create a calorie counter the standard input goes like this:
python3 calories.txt < test.txt
Inside calories the food is the following format: apples 500
The problem I am having is that whenever I calculate the values for the person it seems to never return to an empty list..
import sys
food = {}
eaten = {}
finished = {}
total = 0
#mappings
def calories(x):
with open(x,"r") as file:
for line in file:
lines = line.strip().split()
key = " ".join(lines[0:-1])
value = lines[-1]
food[key] = value
def calculate(x):
a = []
for keys,values in x.items():
for c in values:
try:
a.append(int(food[c]))
except:
a.append(100)
print("before",a)
a = []
total = sum(a) # Problem here
print("after",a)
print(total)
def main():
calories(sys.argv[1])
for line in sys.stdin:
lines = line.strip().split(',')
for c in lines:
values = lines[0]
keys = lines[1:]
eaten[values] = keys
calculate(eaten)
if __name__ == '__main__':
main()
Edit - forgot to include what test.txt would look like:
joe,almonds,almonds,blue cheese,cabbage,mayonnaise,cherry pie,cola
mary,apple pie,avocado,broccoli,butter,danish pastry,lettuce,apple
sandy,zuchini,yogurt,veal,tuna,taco,pumpkin pie,macadamia nuts,brazil nuts
trudy,waffles,waffles,waffles,chicken noodle soup,chocolate chip cookie

Answer 1

How to make it easier on yourself:
When reading the calories-data, convert the calories to int() asap, no need to do it every time you want to sum up somthing that way.
Dictionary has a .get(key, defaultvalue) accessor, so if food not found, use 100 as default is a 1-liner w/o try: ... except:
This works for me, not using sys.stdin but supplying the second file as file as well instead of piping it into the program using <.
I modified some parsings to remove whitespaces and return a [(name,cal),...] tuplelist from calc.
May it help you to fix it to your liking:
def calories(x):
with open(x,"r") as file:
for line in file:
lines = line.strip().split()
key = " ".join(lines[0:-1])
value = lines[-1].strip() # ensure no whitespaces in
food[key] = int(value)
def getCal(foodlist, defValueUnknown = 100):
"""Get sum / total calories of a list of ingredients, unknown cost 100."""
return sum( food.get(x,defValueUnknown ) for x in foodlist) # calculate it, if unknown assume 100
def calculate(x):
a = []
for name,foods in x.items():
a.append((name, getCal(foods))) # append as tuple to list for all names/foods eaten
return a
def main():
calories(sys.argv[1])
with open(sys.argv[2]) as f: # parse as file, not piped in via sys.stdin
for line in f:
lines = line.strip().split(',')
for c in lines:
values = lines[0].strip()
keys = [x.strip() for x in lines[1:]] # ensure no whitespaces in
eaten[values] = keys
calced = calculate(eaten) # calculate after all are read into the dict
print (calced)
Output:
[('joe', 1400), ('mary', 1400), ('sandy', 1600), ('trudy', 1000)]
Using sys.stdin and piping just lead to my console blinking and waiting for manual input - maybe VS related...