使用 dict.clear() 删除所有值我怎样才能坚持字典值？

问题描述

带注释的代码：

result = {}

def number_of_products():
    return 1 # 2,3...n

def total_inventory():
    return 100 # 200,300... n

def set_values():
    result["numberOfProducts"] = number_of_products()
    result["totalInventory"] = total_inventory()

def run_orders():
    results = []
    for i in range(4):
         set_values()
         
         # result = {'numberOfProducts': 1,'totalInventory': 1000} for the first iteration
         # result = {'numberOfProducts': 2,'totalInventory': 2000} for the first iteration
         ...
         
         # Add result to the array for future use. 
         results.append(result)

         # Clean up the dictionary for reuse. 
         result.clear()

    print(results)

    # Expectation
    # [{'numberOfProducts': 1,'totalInventory': 1000},{'numberOfProducts': 2,'totalInventory': 2000},...]

    # Actual
    # [{},{},...]

run_orders()

如您所见，当我使用 .clear() 方法时，数组中出现空值。

我也尝试使用 result = {} 但结果如下：

[{'numberOfProducts': 1,{'numberOfProducts': 1,...]

如何保留从不同结果中获得的值？

解决方法

使用全局 dict 的理由真的为零，只需为每个结果创建一个新的 dict。事实上，“set_values”可能应该返回一个新的字典：

def number_of_products():
    return 1 # 2,3...n

def total_inventory():
    return 100 # 200,300... n

def get_values():
    return {
        "numberOfProducts": number_of_products(),"totalInventory": total_inventory()
    }

def run_orders():
    results = []

    for _ in range(4):
         result = get_values()
         results.append(result)

    print(results)

run_orders()