python csv into dictionary

Question

I am pretty new to python. I need to create a class that loads csv data into a dictionary.

I want to be able to control the keys and value So let say the following c

Answer 1

Have you looked at the csv module?

import csv

Answer 2

import csv

reader = csv.reader(open('workers.csv', newline=''), delimiter=',', quotechar='"')
workers = [ageName(row[0], row[1]) for row in reader]

workers now has a list of all the workers

>>> workers[0].name
'jon'

added edit after question was altered

Is there any reason you're using old style classes? I'm using new style here.

class Student:
    sports = []
    def __init__(self, row):
       self.lname, self.fname, self.ID, self.sport = row
       self.sports.append(self.sport)
    def get(self):
       return (self.lname, self.fname, self.ID, self.sport)

reader = csv.reader(open('copy-john.csv'), delimiter=',', quotechar='"')
print "%-14s|%-10s|%-5s|%-11s" % tuple(reader.next()) # read header line from csv
print "-" * 45
students = list(map(Student, reader)) # read all remaining lines
for student in students:
    print "%-14s|%-10s|%-5s|%3s" % student.get()

# Printing all sports that are specified by students
for s in set(Student.sports): # class attribute
    print s, Student.sports.count(s)

# Printing sports that are not picked 
allsports = ['Basketball','Football','Other','Baseball','Handball','Soccer','Volleyball','I do not like sport']
for s in set(allsports) - set(Student.sports):
    print s, 0

Hope this gives you some ideas of the power of python sequences. ;)

edit 2, shortened as much as possible... just to show off :P

Ladies and gentlemen, 7(.5) lines.

allsports = ['Basketball','Football','Other','Baseball','Handball',
             'Soccer','Volleyball','I do not like sport']
sports = []
reader = csv.reader(open('copy-john.csv'))
for row in reader:
    if reader.line_num: sports.append(s[3])
    print "%-14s|%-10s|%-5s|%-11s" % tuple(s)
for s in allsports: print s, sports.count(s)

Answer 3

I know this is a pretty old question, but it's impossible to read this, and not think of the amazing new(ish) Python library, pandas. Its main unit of analysis is a think called a DataFrame which is modelled after the way R handles data.

Let's say you have a (very silly) csv file called example.csv which looks like this:

day,fruit,sales
Monday,Banana,10
Monday,Orange,20
Tuesday,Banana,12
Tuesday,Orange,22

If you want to read in a csv in double-quick time, and do 'stuff' with it, you'd be hard pressed to beat the following code for either brevity or ease of use:

>>> import pandas as pd
>>> csv = pd.read_csv('example.csv')
>>> csv
       day   fruit  sales
0   Monday  Banana     10
1   Monday  Orange     20
2  Tuesday  Banana     12
3  Tuesday  Orange     22
>>> csv[csv.fruit=='Banana']
       day   fruit  sales
0   Monday  Banana     10
2  Tuesday  Banana     12
>>> csv[(csv.fruit=='Banana') & (csv.day=='Monday')]
      day   fruit  sales
0  Monday  Banana     10

In my opinion, this is really fantastic stuff. Never iterate over a csv.reader object again!

Answer 4

I second Mark's suggestion. In particular, look at DictReader from csv module that allows reading a comma separated (or delimited in general) file as a dictionary.

Look at PyMotW's coverage of csv module for a quick reference and examples of usage of DictReader, DictWriter