Python read CSV to string conversion

Question

I have a CSV with following values

ID, Value
1, a
2, b
3, c

How can I convert this csv to following string using Python

[('ID', 'Value'), (1, 'a'), (2, 'b'), (3, 'c')]

I was trying with the following code

with open('sample.csv', 'rb') as csvfile: 
    reader = csv.reader(csvfile, delimiter=' ', quotechar='|')
    for row in reader:
        data = ', '.join(row)
        rows.append(data)
print rows

Am getting following output only

["'ID','Value'", "1,'a'", "2,'b'", "3,'c'"]

Answer 1

Do not read with rb but just r :

with open('sample.csv', 'r') as csvfile:
    csvtext = csvfile.readlines()

mylist = []
for line in csvtext:
    mylist.append(tuple(line.strip().split(', ')))
print(mylist)

Answer 2

To produce the list [('ID', 'Value'), (1, 'a'), (2, 'b'), (3, 'c')] from that CSV data you need to convert the number strings to integer. Here's one way to do that in Python 2.

import csv

data = []
with open('sample.csv', 'rb') as csvfile: 
    reader = csv.reader(csvfile, skipinitialspace=True)
    data.append(tuple(next(reader)))
    for num, val in reader:
        data.append((int(num), val))

print data

output

[('ID', 'Value'), (1, 'a'), (2, 'b'), (3, 'c')]

---

The csv.reader yields each row of the CSV data as a list. We need to extract the items from that list and convert the 1st one to an int . And then we can pack the two items into a tuple and append it to the data list. However, the header line contains two strings, so we don't want to perform that conversion on the header line.

This code:

data.append(tuple(next(reader)))

gets the header line and just converts it to a tuple and appends the result to our data list.

---

Note that the Python 2 csv module requires you to open the file in 'rb' mode, but in Python 3 you need to open the file in 'r' mode. Please see the respective module docs for further details. Apart from that, and using the print function instead of the print statement, no other changes are needed to run the above code on Python 3.