Python，合并字典

Question

I'm learning python and here I have a task. I'm trying to figure out how can I merge dictionaries selecting them by one Key and update the remaining values. Here are the dictionaries:

• act1= {'name': 'Max', 'day':1, 'payment (dollars)': 2}
• act2= {'name': 'Tom', 'day':3, 'payment (dollars)': 5}
• act3= {'name': 'Alison', 'day':2, 'payment (dollars)': 3}
• act4= {'name': 'Pascal', 'day':3, 'payment (dollars)': 8}
• act5= {'name': 'Tom', 'day':7, 'payment (dollars)': 6}
• act6= {'name': 'Max', 'day':2, 'payment (dollars)': 1}
• act7= {'name': 'Tom', 'day':8, 'payment (dollars)': 8}

the result i'm trying to obtain could be represented like this:

• payment_max={'name': 'Max', 'day':'day1+day2', payment (dollars)': 2+1}
• payment_tom={'name': 'Tom', 'day':'day3+day7+day8','payment (dollars)': 5+6+8}
• payment_alison={'name': 'Alison','day':'day3', 'payment (dollars)': 3}
• pascal={'name': 'Pascal','day':'day3','payment (dollars)': 8}

I'm just beginning in programming, and this question could have a very evident solution, but i'm a bit confused trying to find it out

thak you very much

Answer 1

I don't know if you want a bunch of variable names versus making a list, but in either case here's one possible way to do it:

act1= {'name': 'Max', 'day':1, 'payment (dollars)': 2}
act2= {'name': 'Tom', 'day':3, 'payment (dollars)': 5}
act3= {'name': 'Alison', 'day':2, 'payment (dollars)': 3}
act4= {'name': 'Pascal', 'day':3, 'payment (dollars)': 8}
act5= {'name': 'Tom', 'day':7, 'payment (dollars)': 6}
act6= {'name': 'Max', 'day':2, 'payment (dollars)': 1}
act7= {'name': 'Tom', 'day':8, 'payment (dollars)': 8}

# make variables into list for easier handling (or just start with one, hopefully)
def take_act_vars_to_list():
    global_vars = globals()
    act_list = []
    for num in range(1, 8):  # this is hardcoded, but could be inferred
        key_now = "act" + str(num)
        assert(key_now in global_vars)  # check that the variable exists
        act_list.append(global_vars[key_now])
    return act_list

# merge and update dictionary elements
def update_dict(dict_to_update, reference_dict):
    # update dictionary from the duplicate references
    for key in reference_dict:
        if key is not "name":
            if key in dict_to_update:
                dict_to_update[key] += reference_dict[key]
            else:  # make new key and entry
                dict_to_update[key] = reference_dict[key]
    return

act_list = take_act_vars_to_list()
merged_vars = {}
for dict_now in act_list:  # iterate over dictionary entries
    name_now = dict_now["name"]  # want to merge based on name
    if name_now not in merged_vars:  # initialize a new dictionary
        merged_vars[name_now] = {}
        update_dict(merged_vars[name_now], dict_now)
    else:  # update existing dictionary
        sub_dict = merged_vars[name_now]
        update_dict(sub_dict, dict_now)

For this example the result of merged_vars is

{'Max': {'day': 3, 'payment (dollars)': 3}, 'Tom': {'day': 18, 'payment (dollars)': 19}, 'Alison': {'day': 2, 'payment (dollars)': 3}, 'Pascal': {'day': 3, 'payment (dollars)': 8}}