Work-in-progress solution to pre-release problem (Feb 2020)

gravel.py

def name(sack_type):
    if sack_type == 'S': return 'sand'
    elif sack_type == 'G': return 'gravel'
    elif sack_type == 'C': return 'cement'

def input_sack_details(n):
    global NREJECTS
    while True:
        prompt = "Sack " + str(n) + "> "
        user_input = input(prompt)
        sack_type, weight = user_input.split()
        weight = float(weight)
        if sack_type not in ['S', 'G', 'C']:
            print(" *** Invalid sack type")
            NREJECTS += 1
            continue
        if sack_type == 'S' or sack_type == 'G':
            if weight <= 49.9 or weight >= 50.1:
                print(" * Rejected: weight not in range")
                NREJECTS += 1
                continue
        if sack_type == 'C':
            if weight <= 24.9 or weight >= 25.1:
                print(" * Rejected: weight not in range")
                NREJECTS += 1
                continue
        # If we get this far, the input was valid.
        TYPES.append(sack_type)
        WEIGHTS.append(weight)
        print(" * Accepted: %s %f kg" % (name(sack_type), weight))
        return

def print_summary():
    pass

# ------------------------------------------------------------------------------

# Key variables.
N = 0
TYPES = []
WEIGHTS =[]
NREJECTS = 0

# Ask user for number of sacks.
N = int(input("Number of sacks> "))

# Loop, accepting user input and updating variables, then print summary.
nsacks = 0          # The number accepted so far. Loop until we have enough.
while nsacks < N:
    input_sack_details(nsacks+1)
    nsacks += 1
print_summary()