添加到地图列表或更新以前添加的地图的值aws-dynamodb

Question

我的Dynamodb中有一个类型为'List of Maps'的属性。例如，List=[{key1:value1}，{key2:value2}，{key3:value3}，...]我想用current_key更新列表（来自我的python脚本）以添加一个新键，或者如果current_key已经存在，则替换该值。

Answer 1

为了更好地演示下面的代码，我选择将{key1:value1}更改为字符串。从功能上讲，当您调用add_to_datalist函数时，应该没有区别。

def add_to_datalist(datalist, key, value):
    check = 0 
#check is needed to ensure the if condition after the for loop can trigger
    for datadict in datalist:
        if key in datadict.keys():
            datadict[key] = value
            check = 1 #turn off check if a key matching is found

    if check == 0:
        datalist.append({key:value})

    return datalist



datalist = [{'key1':'value1'},{'key2':'value2'},{'key3':'value3'}]

key1 = 'key333'
value1 = 'value999'
datalist = add_to_datalist(datalist, key1, value1)
key2 = 'key2'
value2 = 'valueNEW2'
datalist = add_to_datalist(datalist, key2, value2)

print (datalist)
#[{'key1': 'value1'}, {'key2': 'valueNEW2'}, {'key3': 'value3'}, {'key333': 'value999'}]