''' csv_to_list_of_records.py
convert a comma separated value (csv) string to a list of records
then do some processing
tested with Python34  by  vegaseat  08apr2015
'''

import operator as op

class Persons:
    ''' mimics a record '''
    def __init__(self, name, age, weight, seniority, pay):
        self.name = name
        self.age = age
        self.weight = weight
        self.seniority = seniority
        self.pay = pay
        
    
# a csv test string with lines of 
# comma separated values (csv)
# could have come from a csv file
# name,age,weight,seniority,pay
csv_str = '''\
Bob,34,121,13,69000
Zoe,19,63,2,23300
Amy,45,59,5,45000
Frank,56,93,12,57000
Kaka,23,55,7,45000
Udo,27,65,3,39000
Vera,31,71,8,45000
Betty,22,77,5,45000'''

# convert to a list of records
record_list = []
for line in csv_str.split('\n'):
    name, age, weight, seniority, pay = line.split(",")
    record = Persons(name, age, weight, seniority, pay)
    record_list.append(record)

print("Do some data processing with the list of records:")
pay_list = []
seniority_list = []
for person in record_list:
    print("{:<8} makes ${} per year".format(person.name, person.pay))
    pay_list.append(float(person.pay))
    seniority_list.append(float(person.seniority))

print('-'*32)

print("Minimum pay = {}".format(min(pay_list)))
print("Maximum pay = {}".format(max(pay_list)))
sf = "Average pay in department = ${:0.2f}"
print(sf.format(sum(pay_list)/len(pay_list)))
print("Total seniority = {:0.1f} years".format(sum(seniority_list))) 
sf = "Average seniority in department = {:0.1f} years"
print(sf.format(sum(seniority_list)/len(seniority_list)))

''' result ...
Do some data processing with the list of records:
Bob      makes $69000 per year
Zoe      makes $23300 per year
Amy      makes $45000 per year
Frank    makes $57000 per year
Kaka     makes $45000 per year
Udo      makes $39000 per year
Vera     makes $45000 per year
Betty    makes $45000 per year
--------------------------------
Minimum pay = 23300.0
Maximum pay = 69000.0
Average pay in department = $46037.50
Total seniority = 55.0 years
Average seniority in department = 6.9 years

'''

print('-'*32)

# sorting, first by pay then name (case of equal pay)
for person in sorted(record_list, key=op.attrgetter('pay', 'name')):
    print("{:<8} {}".format(person.name, person.pay))
    
''' result ...
Zoe      23300
Udo      39000
Amy      45000
Betty    45000
Kaka     45000
Vera     45000
Frank    57000
Bob      69000

'''
2
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Discussion Span
Last Post by vegaseat
2

Hi,

Example reading the data from a "csv_str.csv" file:

# convert to a list of records
record_list = []
with open ("csv_str.csv",'r') as fi:        
    reader = csv.reader(fi,delimiter=',')
    for line in reader:
        name, age, weight, seniority, pay = line
        record = Persons(name, age, weight, seniority, pay)
        record_list.append(record)

Don't forget to import the csv library import csv

0

Thanks for showing how to read the csv file directly. For testing purposes it was simpler to use the string in the code.

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