Add to a list of maps or update value of previously added map aws-dynamodb

Question

I have a attribute of type 'List of maps' in my dynamodb. e.g. List = [{key1: value1},{key2: value2},{key3:value3},...] I want to update the list (from my python script) with current_key to add a new key or replace the value if the current_key is already present.

Answer 1

To illustrate the code below better, I've chosen to change your {key1:value1} to strings. Functionally, when you are calling the add_to_datalist function, there should be no difference.

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'}]