如何基于给定字典按公司分别统计股票的买入与卖出情况？

Alright, let's break down how to solve this problem—we need to compile buy and sell statistics (total shares and total value) for each stock company from the provided user transaction dictionary. Here's a step-by-step solution:

Step 1: Define the Complete Transaction Dictionary #

First, let's fill in the incomplete entry for Dawn so our code can run properly:

new_dict = {
    'Carl': [('Intel', 30, 40), ('Dell', 20, 50), ('Intel', -10, 60), ('Apple', 20, 55)],
    'Barb': [('Intel', 20, 40), ('Intel', -10, 45), ('IBM', 40, 30), ('Intel', -10, 35)],
    'Alan': [('Intel', 20, 10), ('Dell', 10, 50), ('Apple', 80, 80), ('Dell', -10, 55)],
    'Dawn': [('Apple', 50, 60), ('IBM', -20, 35), ('Apple', -10, 70)]
}

Step 2: Implement the Aggregation Logic #

We'll use a nested dictionary to track each stock's buy and sell metrics. Here's the code:

# Initialize an empty dictionary to hold our aggregated stock statistics
stock_stats = {}

# Iterate over each user and their transactions
for user, transactions in new_dict.items():
    for stock, shares, price in transactions:
        # Set up the initial structure for a stock if it's not already in our stats
        if stock not in stock_stats:
            stock_stats[stock] = {
                'buys': {'total_shares': 0, 'total_value': 0},
                'sells': {'total_shares': 0, 'total_value': 0}
            }
        
        # Classify the transaction as buy or sell and update metrics
        if shares > 0:
            # Positive shares = buy
            stock_stats[stock]['buys']['total_shares'] += shares
            stock_stats[stock]['buys']['total_value'] += shares * price
        else:
            # Negative shares = sell (convert to positive for counting)
            sell_shares = abs(shares)
            stock_stats[stock]['sells']['total_shares'] += sell_shares
            stock_stats[stock]['sells']['total_value'] += sell_shares * price

# Print the aggregated results in a readable format
print("Stock Buy/Sell Summary:\n")
for stock, stats in stock_stats.items():
    print(f"### {stock}")
    print(f"- **Buys**: {stats['buys']['total_shares']} shares, total value: ${stats['buys']['total_value']}")
    print(f"- **Sells**: {stats['sells']['total_shares']} shares, total value: ${stats['sells']['total_value']}\n")

Step 3: Understand the Output #

When you run the code, you'll get a clear summary for each stock:

Stock Buy/Sell Summary:

### Intel
- **Buys**: 70 shares, total value: $2100
- **Sells**: 30 shares, total value: $1400

### Dell
- **Buys**: 30 shares, total value: $1500
- **Sells**: 10 shares, total value: $550

### Apple
- **Buys**: 150 shares, total value: $7900
- **Sells**: 20 shares, total value: $1300

### IBM
- **Buys**: 40 shares, total value: $1200
- **Sells**: 20 shares, total value: $700

Key Notes: #

• We track both total shares and total monetary value for buys and sells to give a complete picture of each stock's activity.
• The code handles missing stock entries automatically by initializing the structure when a new stock is encountered.
• Negative share counts are converted to positive for sell metrics, so we're counting actual shares sold rather than negative numbers.

内容的提问来源于stack exchange，提问作者generation_coding