How to read a csv file with python

Question

I\'m trying to read a csv file but it doesn\'t work. I can read my csv file but when I see what I read, there where white space between values.

Here is my code

Answer 1

I prefer to use numpy's genfromtxt rather than the standard csv library, because it generates numpy's recarray, which are clean data structures to store data in a table-like object.

>>> from numpy import genfromtxt
>>> data = genfromtxt(csvfile, delimiter=',', dtype=None)
# data is a table-like structure (a numpy recarray) in which you can access columns and rows easily
>>> data['firstcolumn']
<content of the first column>

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EDIT: This answer is quite old. While numpy.genfromtxt, nowadays most people would use pandas:

>>> import pandas as pd
>>> pd.read_csv(csvfile)

This has the advantage of creating pandas.DataFrame, which is a better structure for data analysis.

Answer 2

If you have control over the data, use tab-delimited instead::

import csv
import string

writer = open('junk.txt', 'wb')
for x in range(10):
    writer.write('\t'.join(string.letters[:5]))
    writer.write('\r\n')
writer.close()
reader = csv.reader(open('junk.txt', 'r'), dialect='excel-tab')
for line in reader:
    print line

This produces expected results.

A tip for getting more useful feedback: Demonstrate your problem through self-contained and complete example code that doesn't contain extraneous and unimportant artifacts.

Answer 3

You don't do anything with the dialect you've defined. Did you mean to do this:

csv.register_dialect('windows_dialect', windows_dialect)
p = csv.reader(contenu, dialect='windows_dialect')

Also not sure what the reco function is for.