我考虑了一会儿是否应该回答这个问题。
我100%同意，它看起来像你没有投入太多，如果有的话，努力到这一点之前，问它在这里。
它看起来也很像家庭作业中的复制/粘贴问题。

尽管如此

我已经花时间为你标记了每一行代码，我相信你会至少花时间仔细检查这段代码并学习它的功能。这都是非常简单的东西。如果你需要任何解释，我很乐意进一步帮助你。

# Open the file
file = 'C:\\PATH\\TO\\FILE\\orders.txt'
with open(file, 'r') as f:
    # Read the contents of the file into a list of lines
    lines = f.readlines()

# Initialize a dictionary to store the sales totals for each OrderID
sales_totals = {}

# Iterate over the lines, skipping first line which is column names
for line in lines[1:]:
    # Skip over blank lines in the textfile
    if line == '\n':
        continue

    # Split the line into a list of values, we are telling it to split on each comma
    values = line.strip().split(',')

    # Get the OrderID and Sales values
    # index's start at 0. Since order_id is the first column, it's index 0
    order_id = values[0]

    # sales is in the third column, since it start's from 0, that's index 2
    # we are also converting this string into a float so that we can perform
    # math functions on it later
    sales = float(values[2])

    # Add the Sales value to the total for the OrderID
    if order_id in sales_totals:
        # This is not the first occurrence of this order_id
        # so you want to add to the current sales total for this id
        sales_totals[order_id] += sales
    else:
        # This is the first occurrence of this order_id
        sales_totals[order_id] = sales

# Print the sales totals for each OrderID
for order_id, total in sales_totals.items():
    print(f'Order {order_id}: {total}')