print("""
#   simple summing use cases.
sales_by_region = {
    'North': 1120, 
    'South': 2100, 
    'East': 3219, 
    'West': 4050}
total_sales = 0
for sales_amount in sales_by_region.values():
    total_sales += sales_amount
print(f"Total sales across all regions: {total_sales}")""")
#   simple summing use cases.
sales_by_region = {
    'North': 1120, 
    'South': 1120, 
    'East': 3219, 
    'West': 4050}
total_sales = 0
print(f"sales_by_region.values(): {sales_by_region.values()}")
for sales_amount in sales_by_region.values():
    total_sales += sales_amount
print(f"Total sales across all regions: {total_sales}") 
 
# version #2:
print('print(f"Total sales across all regions: {sum(sales_by_region.values())}")')
print(f"Total sales across all regions: {sum(sales_by_region.values())}")

# version #3:
total_sales = 0
print(f"sales_by_region.items(): {sales_by_region.items()}")
for _, sales_amount in sales_by_region.items(): #_: anonymous variable
#   a placeholder to store a value that you are not using.
    total_sales += sales_amount
print(f"Total sales across all regions: {total_sales}")