修改字典python中的值

问题描述

我有一个使用itertools的文本文件字典。

import itertools

plantfile = 'myplants.txt' #file path
plant = {} #create an empty dictionary
with open(plantfile,'r') as f:
    for empty_line,group in itertools.groupby(f,lambda x: x == '\n'): 
        if empty_line:
            continue
        fruit,*desc = map(str.strip,group)
        plant[fruit] = desc

结果是：

{'banana' : ['delicIoUs','yellow'],'watermelon' : ['big','red'],'orange' : ['juicy','vitamin c']} 

我想提示用户水果（键）的名称以同时修改键和描述（值）或删除整个记录。如果可以使用def（）函数，那将是最好的。

以下是我当前的代码。它们不会向我返回任何错误消息，但是，它们也不会反映在字典文件中。

    print("What do you want to do with this database?
    1. Modify fruit information
    2. Delete fruit record")
    
    choice == input("Please enter your choice in number: ")
    
    while True:
        try:
            if choice == '1':
               original_name = input("What is the fruit name you would like to modify?").upper()
               new_name = input("What is the new fruit name?")
            
               with open(file,'r+') as f: 
               string = f.read() 
               string = string.replace(original_name,new_name) 
               f.truncate(0) 
               f.seek(0) 
               f.write(string) #writeback to file
               print(f"You have modified {original_name} to {new_name}.")
               break
            else:
               delname = input("Please enter the name of the fruit: \n").upper() 
               delname = dict(filter(lambda item: delname in item[0],plant.items())) 
               break
except ValueError:
    print("Invalid input. Please try again.")

我不知道如何修改值，并且上述修改键名的代码似乎也不起作用。

上面删除整个记录的代码也没有反映在原始文件中。

例如，我想将西瓜的价值从“大”更改为“硬”，并希望删除整个香蕉记录。

{'watermelon' : ['hard','vitamin c']} 

请帮帮我。谢谢

解决方法

此解决方案适用于编辑之前的问题。先前进行的.upper()输入中有一个original_name。修改后的代码如下：

import itertools

file = 'file.txt' 
plant = {} 
with open(file,'r') as f:
    for empty_line,group in itertools.groupby(f,lambda x: x == '\n'): 
        if empty_line:
            continue
        fruit,*desc = map(str.strip,group)
        plant[fruit] = desc

print(plant)


original_name = input("What is the fruit name you would like to modify?")
new_name = input("What is the new fruit name?")
    
with open(file,'r+') as f: 
    string = f.read()
    string = string.replace(original_name,new_name) 
    f.seek(0) 
    f.write(string) #writeback to file
print(f"You have modified {original_name} to {new_name}.")

假设您的file.txt如下所示：

banana
delicious,yellow

watermelon
big,red

orange
juicy,vitamin cc