I have a class called transaction that have these attributes

Transaction([time_stamp, time_of_day, day_of_month ,week_day, duration, amount, trans_type,
location])

an example of the data set is as such

timestamp   time    date    weekday duration    amount  trans_type      location
1           0:07    3       thu      2                  balance         driveup
2           0:07    3       thu      6          20      withdrawal      campus a
3           0:20    1       tue      2          357     advance         driveup
4           0:26    3       thu      2          20      withdrawal      campus b
5           0:26    4       fri      2          35       deposit            driveup

There are different transaction types. define in trans_type which are:

advance, balance, deposit, transfer, withdrawal 

How do I calculate the percentage types of transaction?

For example, this will be the resulting list:

[('advance', 20), ('balance', 20), ('deposit', 20), ('transfer', 0), ('withdrawal', 40)]

This is what i have tried:

#percentage of the different types of transactions
advance = 0
balance = 0
deposit = 0
transfer = 0
withdrawal = 0
for element in range(len(atm_transaction_list)):for trans_type in element:if trans_type == 'advance':advance += 1elif trans_type == 'balance':balance += 1elif trans_type == 'deposit':deposit += 1elif trans_type == 'transfer':transfer += 1elif trans_type == 'withdrawal':withdrawal += 1

With for element in range(len(atm_transaction_list)):, you are iterating over integers in a range. This is generally used when you want to work with indices. However, you're not doing that. Simply iterate over the transaction list itself, with for transaction in atm_transaction_list:. Each transaction will then be a Transaction object.

I would also recommend storing your results in a dictionary instead of in five separate references. You can then add to a key's value whenever it's seen.

result = {'advance':0, 'balance':0, 'deposit':0, 'transfer':0, 'withdrawal':0}
for element in atm_transaction_list:result[element.trans_type] += 1

This will give you a dictionary that you can access with something like result['advance'] to see the number of 'advance' transactions.

Now divide each key's value by the total number of transactions and multiply by 100 to get the percentage:

l = len(atm_transaction_list)
for key in result:result[key] = result[key] / l * 100