csv_example.py

#!/usr/bin/env python

"""
Example of how to save data as an CSV file with the CSV module

"""

import csv

outfilename = "add_book_data.csv"

# get the data from the py file
# csv format really only holds flat data well.
from add_book_data_flat import AddressBook

# create a csv file writing object
writer = csv.writer( open(outfilename, 'wb') )

# write the headers
# assume all data have the same keys
headers = AddressBook[0].keys()
writer.writerow ( headers )

for person in AddressBook:
    row = [person[key] for key in headers]
    writer.writerow(row)    

del writer # to make sure the file gets closed

### see if it can be re-loaded.

# create a csv file reading object
reader = csv.reader( open(outfilename, 'rb') )
# read  the headers
headers = reader.next() # it's an iterator -- so next() gives us the next row -- in this case, the first row

# build up the new version:
AddressBook2 = []
for row in reader:
    AddressBook2.append(dict(zip(headers, row)))

del reader # to make sure the file is closed

#Check if they are the same
if AddressBook2 == AddressBook:
    print "csv readr version is the same as the original"

## or use the built-in "DictReader":

# create a DictReader file reading object
reader = csv.DictReader( open(outfilename, 'rb') )
# no need to read  the headers -- it will use the first row

# build up the new version:
AddressBook3 = []
for row in reader:
    print "row:", row
    AddressBook3.append(row)

del reader # to make sure the file is closed

#Check if they are the same
if AddressBook3 == AddressBook:
    print "The DictReader one is the the same"