石头剪刀布游戏中的“全局”头痛

Question

I am trying to write python code related to water, snake and gun game (Rock, Paper, Scissor).

If I use this code:

import random
usscore = 0
pcscore = 0

wsg = ["Water", "Snake", "Gun"]
inp = [1,2,3]
wsginputT = 0
wsginpw = ""

def wsgf(wsginpw,compran,pcscore,wsginput,usscore):
    if wsginpw == compran:
        print("AARGH its a draw")
        pass
    else:
        if wsginput == 1 and compran == wsg[1]:#WATER VS SNAKE
            print("LOLLL")
            print("HAHA Snake drunk all the water")
            pcscore = pcscore +1
        else:
            if wsginput == 1 and compran == wsg[2]:#WATER VS GUN
                print("Hmmmm will see ya next time! ")
                print("Gun had no chance against WATER")
                usscore = usscore + 1
            else:
                if wsginput == 2 and compran == wsg[0]:#SNAKE VS WATER
                    print("Hmmmm will see ya next time! ")
                    print("HUH Your snake drunk all the water")
                    usscore = usscore + 1
                else:
                    if wsginput == 2 and compran == wsg[2]:#SNAKE VS GUN
                        print("LOLLL")
                        print("HAHA My Gun killed your snake")
                        pcscore = pcscore + 1
                    else:
                        if wsginput == 3 and compran == wsg[0]:#GUN VS WATER
                            print("LOLLL ")
                            print("HAHA your gun is drowned in water!")
                            pcscore = pcscore + 1
                        else:
                            if wsginput == 3 and compran == wsg[1]:#GUN VS SNAKE
                                print("Hmmmm will see ya next time!")
                                print("Not Fair my snake was killed by your gun")
                                usscore = usscore + 1
    print("Pc score",pcscore, "User Score", usscore)

for ten in range(10):
    while True:
        try:
            wsginput = int(input("""Please enter
                             1 FOR WATER
                             2 FOR SNAKE
                             3 FOR GUN\n"""))
            if wsginput in inp:
                break
            else:
                print("Please enter value between 1 and 3 inclusive")
                continue

        except:
            print("Please enter a valid integer")
            continue

    wsginpw = wsg[wsginput-1]
    # print(wsginpw)

    compran = random.choice(wsg)
    # print(compran)
    wsgf(wsginpw,compran,pcscore,wsginput,usscore)

print("Your score is ", usscore)
print("Computer's score is ", pcscore)
if usscore > pcscore:
    print("You Won")
else:
    print("You Lose")

The score I receive at end is 0 . You can run it.

The problem solved by introducing global function and code runs smoothly but I remember someone saying not to use global in question Headbutting UnboundLocalError (blah…blah…blah)

The code with global s is as follows:

import random
usscore = 0
pcscore = 0

wsg = ["Water", "Snake", "Gun"]
inp = [1,2,3]
wsginputT = 0
wsginpw = ""

def wsgf():
    global wsginpw
    global compran
    global pcscore
    global wsginput
    global usscore

    if wsginpw == compran:
        print("AARGH its a draw")
        pass
    else:
        if wsginput == 1 and compran == wsg[1]:#WATER VS SNAKE
            print("LOLLL")
            print("HAHA Snake drunk all the water")
            pcscore = pcscore +1
        else:
            if wsginput == 1 and compran == wsg[2]:#WATER VS GUN
                print("Hmmmm will see ya next time! ")
                print("Gun had no chance against WATER")
                usscore = usscore + 1
            else:
                if wsginput == 2 and compran == wsg[0]:#SNAKE VS WATER
                    print("Hmmmm will see ya next time! ")
                    print("HUH Your snake drunk all the water")
                    usscore = usscore + 1
                else:
                    if wsginput == 2 and compran == wsg[2]:#SNAKE VS GUN
                        print("LOLLL")
                        print("HAHA My Gun killed your snake")
                        pcscore = pcscore + 1
                    else:
                        if wsginput == 3 and compran == wsg[0]:#GUN VS WATER
                            print("LOLLL ")
                            print("HAHA your gun is drowned in water!")
                            pcscore = pcscore + 1
                        else:
                            if wsginput == 3 and compran == wsg[1]:#GUN VS SNAKE
                                print("Hmmmm will see ya next time!")
                                print("Not Fair my snake was killed by your gun")
                                usscore = usscore + 1
    print("Pc score",pcscore, "User Score", usscore)

for ten in range(10):
    while True:
        try:
            wsginput = int(input("""Please enter
                             1 FOR WATER
                             2 FOR SNAKE
                             3 FOR GUN\n"""))
            if wsginput in inp:
                break
            else:
                print("Please enter value between 1 and 3 inclusive")
                continue

        except:
            print("Please enter a valid integer")
            continue

    wsginpw = wsg[wsginput-1]
    # print(wsginpw)

    compran = random.choice(wsg)
    # print(compran)
    wsgf()

print("Your score is ", usscore)
print("Computer's score is ", pcscore)
if usscore > pcscore:
    print("You Won")
else:
    print("You Lose")

Someone please find me a way to not to use global s and please remember I am a beginner and learning. If you use something difficult please explain it as well. Also, any tips on how to shorten my code?

Answer 1

If you don't use global you need to return the variables that you're assigning, so the caller can get the updated values.

def wsgf(wsginpw,compran,pcscore,wsginput,usscore):
    if wsginpw == compran:
        print("AARGH its a draw")
        pass
    else:
        if wsginput == 1 and compran == wsg[1]:#WATER VS SNAKE
            print("LOLLL")
            print("HAHA Snake drunk all the water")
            pcscore = pcscore +1
        else:
            if wsginput == 1 and compran == wsg[2]:#WATER VS GUN
                print("Hmmmm will see ya next time! ")
                print("Gun had no chance against WATER")
                usscore = usscore + 1
            else:
                if wsginput == 2 and compran == wsg[0]:#SNAKE VS WATER
                    print("Hmmmm will see ya next time! ")
                    print("HUH Your snake drunk all the water")
                    usscore = usscore + 1
                else:
                    if wsginput == 2 and compran == wsg[2]:#SNAKE VS GUN
                        print("LOLLL")
                        print("HAHA My Gun killed your snake")
                        pcscore = pcscore + 1
                    else:
                        if wsginput == 3 and compran == wsg[0]:#GUN VS WATER
                            print("LOLLL ")
                            print("HAHA your gun is drowned in water!")
                            pcscore = pcscore + 1
                        else:
                            if wsginput == 3 and compran == wsg[1]:#GUN VS SNAKE
                                print("Hmmmm will see ya next time!")
                                print("Not Fair my snake was killed by your gun")
                                usscore = usscore + 1
    print("Pc score",pcscore, "User Score", usscore)
    return pcscore, usscore

for ten in range(10):
    while True:
        try:
            wsginput = int(input("""Please enter 
                             1 FOR WATER
                             2 FOR SNAKE
                             3 FOR GUN\n"""))
            if wsginput in inp:
                break
            else:
                print("Please enter value between 1 and 3 inclusive")
                continue

        except:
            print("Please enter a valid integer")
            continue

    wsginpw = wsg[wsginput-1]
    # print(wsginpw)

    compran = random.choice(wsg)
    # print(compran)
    pcscore, usscore = wsgf(wsginpw,compran,pcscore,wsginput,usscore)

Answer 2

Honestly, your code is a pain to read. Creating a game of rock/paper/scissors can be simplified to comparing an input X with an input Y, on a 3x3 matrix:

# The matrix defines when the user wins (1), when its a draw (0),
# and when the PC wins (-1)
   
           USER 
          R   P   S
      R [ 0,  1, -1 ]
PC    P [-1,  0,  1 ]
      S [ 1, -1,  0 ]

With that in mind, this little game can be divided into 2 functions: one which ask an input and check if you win or loose, and a second which repeats this first one a certain number of time and keep track of the score.

This is obviously way different from your code, but it's also a cleaner implementation from which I hope you may learn something.

import random
import numpy as np


def rps():
    """
    Ask for input, and compare to a random choice by the pc.

    Returns
    -------
    int
        -1: PC wins, 0: draw, 1: user wins.
    """
    mapping = dict(rock=0, paper=1, scissors=2)
    win_matrix = np.array(
        [[0, 1, -1],
         [-1, 0, 1],
         [1, -1, 0]])
    
    user_input = input('Rock, Paper or Scissors? ').lower().strip()
    assert user_input in mapping, \
        "Input must be one of 'rock', 'paper' or 'scissors'"
    pc_input = random.choice(['rock', 'paper', 'scissors'])
    
    if win_matrix[mapping[pc_input], mapping[user_input]] == 0:
        print ('Draw')
    elif win_matrix[mapping[pc_input], mapping[user_input]] == 1:
        print ('You win!')
    elif win_matrix[mapping[pc_input], mapping[user_input]] == -1:
        print ('The PC win!')

    return win_matrix[mapping[pc_input], mapping[user_input]]
    
def run(n_times):
    """
    Runs the RPS game a certain number of times and keep track of the score.
    """
    user_score = 0
    pc_score = 0
    
    for k in range(n_times):
        result = rps()
        if result == 1:
            user_score += 1
        elif result == -1:
            pc_score += 1
            
    print (f'The score is: [USER] {user_score} -- [PC] {pc_score}')
    
    return user_score, pc_score

if __name__ == '__main__':
    run(5)

But what about the custom messages for each win/loose scenario? Instead of a painful if/elif/else structure (which is not even your case as you used a far worst nested if/else structure), simply define the custom sentence corresponding to each matrix position:

sentences = {
    (0, 0): 'Sentence when rock vs rock',
    (0, 1): 'Sentence when user paper vs pc rock',
    ...
    }

And then use this dictionary in the first function with the variable (mapping[pc_input], mapping[user_input]) .