Python csv string to array

Question

Anyone know of a simple library or function to parse a csv encoded string and turn it into an array or dictionary?

I don't think I want the built in csv module because in all the examples I've seen that takes filepaths, not strings.

Answer 1

Simple - the csv module works with lists, too:

>>> a=["1,2,3","4,5,6"]  # or a = "1,2,3\n4,5,6".split('\n')
>>> import csv
>>> x = csv.reader(a)
>>> list(x)
[['1', '2', '3'], ['4', '5', '6']]

Answer 2

As others have already pointed out, Python includes a module to read and write CSV files. It works pretty well as long as the input characters stay within ASCII limits. In case you want to process other encodings, more work is needed.

The Python documentation for the csv module implements an extension of csv.reader, which uses the same interface but can handle other encodings and returns unicode strings. Just copy and paste the code from the documentation. After that, you can process a CSV file like this:

with open("some.csv", "rb") as csvFile: 
    for row in UnicodeReader(csvFile, encoding="iso-8859-15"):
        print row

Answer 3

https://docs.python.org/2/library/csv.html?highlight=csv#csv.reader

csvfile can be any object which supports the iterator protocol and returns a string each time its next() method is called

Thus, a StringIO.StringIO(), str.splitlines() or even a generator are all good.

Answer 4

The official doc for csv.reader() https://docs.python.org/2/library/csv.html is very helpful, which says

file objects and list objects are both suitable

import csv

text = """1,2,3
a,b,c
d,e,f"""

lines = text.splitlines()
reader = csv.reader(lines, delimiter=',')
for row in reader:
    print('\t'.join(row))

Answer 5

Panda is quite powerful and smart library reading CSV in Python

A simple example here, I have example.zip file with four files in it.

EXAMPLE.zip
 -- example1.csv
 -- example1.txt
 -- example2.csv
 -- example2.txt

---

from zipfile import ZipFile
import pandas as pd


filepath = 'EXAMPLE.zip'
file_prefix = filepath[:-4].lower()

zipfile = ZipFile(filepath)
target_file = ''.join([file_prefix, '/', file_prefix, 1 , '.csv'])

df = pd.read_csv(zipfile.open(target_file))

print(df.head()) # print first five row of csv
print(df[COL_NAME]) # fetch the col_name data

Once you have data you can manipulate to play with a list or other formats.

Answer 6

I would use StringIO:

try:
    # for Python 2.x
    from StringIO import StringIO
except ImportError:
    # for Python 3.x
    from io import StringIO
import csv

scsv = """text,with,Polish,non-Latin,lettes
1,2,3,4,5,6
a,b,c,d,e,f
gęś,zółty,wąż,idzie,wąską,dróżką,
"""

f = StringIO(scsv)
reader = csv.reader(f, delimiter=',')
for row in reader:
    print('\t'.join(row))

simplier version with split() on newlines:

reader = csv.reader(scsv.split('\n'), delimiter=',')
for row in reader:
    print('\t'.join(row))

Or you can simply split() this string into lines using \n as separator, and then split() each line into values, but this way you must be aware of quoting, so using csv module is preferred.