如何优化循环与条件语句？精简石头剪刀布代码冗余if分支

Great question! That tangled web of if/elif statements is tough to read and maintain—let’s rewrite this with a smarter, more scalable approach. Here’s how to clean up your code:

1. Replace Conditional Chains with a Winning Rules Dictionary #

Instead of manually checking every possible pair, we can define a dictionary that maps each choice to the one it beats. This collapses all those repetitive conditionals into just a couple of simple checks.

Example of the rules dictionary:

winning_pairs = {
    "rock": "scissor",
    "scissor": "paper",
    "paper": "rock"
}

This tells us directly: rock beats scissor, scissor beats paper, paper beats rock.

2. Ditch the Global Variable for a Cleaner Loop #

Using a global winner variable to control the game flow is unnecessary. Instead, use a while True loop and break out of it when the user chooses to stop playing—this keeps the code self-contained and easier to follow.

3. Add Input Validation (Optional but Robust) #

To handle typos or invalid entries, we can add checks to ensure players only enter valid choices (rock/paper/scissor) before proceeding.

Full Optimized Code #

def play_rock_paper_scissors():
    winning_pairs = {"rock": "scissor", "scissor": "paper", "paper": "rock"}
    valid_choices = winning_pairs.keys()

    while True:
        # Get and validate Player 1's choice
        while True:
            choice1 = input("Player 1: please choose rock/paper/scissor! ").lower()
            if choice1 in valid_choices:
                break
            print("Invalid choice! Please enter rock, paper, or scissor.")
        
        # Get and validate Player 2's choice
        while True:
            choice2 = input("Player 2: please choose rock/paper/scissor! ").lower()
            if choice2 in valid_choices:
                break
            print("Invalid choice! Please enter rock, paper, or scissor.")
        
        # Determine the winner in 3 simple checks
        if choice1 == choice2:
            print("It's a draw!")
        elif winning_pairs[choice1] == choice2:
            print("Player 1 is the winner, Congrats!!")
        else:
            print("Player 2 is the winner, Congrats!!")
        
        # Ask to play again with validation
        while True:
            answer = input("Do you want to start a new game? (yes/no) ").lower()
            if answer in ["yes", "no"]:
                break
            print("Please enter 'yes' or 'no'.")
        
        if answer == "no":
            print("See you next time!")
            break
        print("Let's start another game!")

play_rock_paper_scissors()

Key Improvements: #

• No redundant conditionals: The dictionary lets us determine the winner in 3 checks instead of 6+ elif statements.
• No global variables: The loop uses while True and break for flow control, making the code more modular.
• Input validation: Players can’t proceed with typos, making the game more user-friendly.
• Scalability: If you ever want to add extended rules (like lizard/spock), just update the winning_pairs dictionary—no need to add dozens of new conditionals.

内容的提问来源于stack exchange，提问作者oussama z