Printing out all duplicates key in python dict-CodePudding

Here is my code

with open('book1.csv', 'r') as f:
for key, value in c.items():
    if value == max_value:
        print(key)
        if key in dict_from_csv.keys():
            print(dict_from_csv[key])

It prints out only 2 keys but I need all duplicate keys.

this is my CSV it consists of name of projects and costs.

my full code is

c = rank(results)

max_value = max(values)

newlist1_value = values
newlist1_value.remove(max(values))

second_max_value = max(newlist1_value)

newlist2_value = newlist1_value
newlist2_value.remove(max(newlist1_value))

third_max_value = max(newlist2_value)

keys = []
mydict = {}

 with open('book1.csv', mode='r') as inp:
    reader = csv.reader(inp)
    dict_from_csv = {rows[2]: rows[3] for rows in reader}
    for key, value in c.items():
    if value == max_value:
        print(key)
        if key in dict_from_csv.keys():
            print(dict_from_csv[key])

my goal is to print out all the duplicate names of projects with all the costs.

CodePudding user response：

When you are creating dict from csv, duplicate keys are overwritten. Use list instead, then keep track of already seen keys in dict. If there are more than 2 values for a given key print them.

with open('book1.csv', 'r') as f:
    reader = csv.reader(f)
    list_from_csv = [[row[2], row[3]] for row in reader]
    max_value = max([x[1] for x in list_from_csv])
    dic = {}
    res = []

    for li in list_from_csv:
    #iterate over project name and and cost
        key, value = li
        # key is name of project, value is cost
        if value == max_value:
            print('max value', *li)
        if key in dic:
       #check if the project name is already in dic where you store values 
       #for same project name append value to already seen values
            dic[key].append(value)
        if key not in dic:
       # if key is not in dic create new with list of value, so you can append to it later 
            dic[key] = [value]
    # print(dic)

    for key, value in dic.items():
    # finally iterate over stored projects with list of values
    # if there are more than one value , it means it has duplicates so 
    # print them
        if len(value) > 1:
            print(key, *value)