'list index out of range‘错误的列表字典值

Question

我创建了这个程序，“种植”西红柿，并为它们分配一个成熟日期(按轮换的单位)。但是，当我尝试使用该日期时，系统返回错误“list index out of range.‘”。我无论如何也不能理解为什么会发生这样的事情。请理解，我是一个初级程序员，所以当我真的在寻找这个问题的答案时，我发现的很多东西对我来说都是胡言乱语。谢谢!

#!/usr/bin/python
# -*- coding: utf-8 -*-
# this code is meant for testing a portion of farmboi simulator.
# this code is not the entire program.

tomato_seeds = 2
tomato_planted = 0
tomato = 0
tomato_id = 0
growing = {}  # keeps track of what items are currently growing
grown = []
turn = 0  # keeps track of what turn the player is on


# actually 'plants' the tomatoes

def plant(crop, amount):  # the error only runs when amount > 1
    global tomato_seeds
    global tomato_planted
    global tomato_id
    global growing
    global grown
    if crop == 'tomato':
        for i in range(amount):
            if tomato_seeds > 0:
                tomato_seeds -= 1
                tomato_planted += 1
                growing['tomato_' + str(tomato_id)] = turn + 5  
                # this creates a library that contains tomatoes and their turn of harvest
                grown.append('tomato_' + str(tomato_id))  
                # this list is so I can run a for loop using numbers (there's probably a better way to do this idk)
                tomato_id += 1
    else:
        print('You do not have any tomato seeds remaining\n')
        print(str(grown))
        print(str(growing))


# checks every loop to see if the tomatoes are ripe

def check_harvest():
    global tomato
    global tomato_planted
    harvested = 0
    for item in range(len(growing)):
        print('checker: ' + str(growing[grown[item]]))
        if growing[grown[item]] == turn:  
        # Im calling the value here the checker (this is also where the error occurrs)
            tomato += 1
            tomato_planted -= 1
            del growing[grown[item]]
            del grown[item]
        if harvested > 0:
            print('You have harvested ' + str(harvested) + ' tomatoes')


while True:
    if input('What would you like to do?\n').lower() == 'plant':
        plant('tomato', 2)

    check_harvest()
    turn += 1
    print('turn: ' + str(turn))

(可能在某处有缩进错误，忽略这一点。我在将它作为代码放入堆栈溢出文本框时遇到了问题)

Answer 1

在函数check_harvest()中，growing字典的长度可能与grown列表的长度不同。

plant()会将amount项目添加到growing，但是，只有一个项目会添加到grown。因此，如果amount大于1，则字典和列表的长度将会不同。

然后，check_harvest()迭代growing的长度，该长度可能比grown更长，这会导致尝试访问grown中超出列表限制的项。

如果缩进这两行，可能会解决这个问题：

            grown.append("tomato_" + str(tomato_id)) #this list is so I can run a for loop using numbers (there's probably a better way to do this idk)
            tomato_id += 1

这样它们就在for循环中：

            for i in range(amount):
                if tomato_seeds > 0:
                    tomato_seeds -= 1
                    tomato_planted += 1
                    growing["tomato_" + str(tomato_id)] = turn + 5 #this creates a library that contains tomatoes and their turn of harvest
                    grown.append("tomato_" + str(tomato_id)) #this list is so I can run a for loop using numbers (there's probably a better way to do this idk)
                    tomato_id += 1

但我不能确定，因为我不是真的理解你的代码。