将字符串列表转换为字符串数组

Question

I have a list of strings where each string is essentially a line of data pulled in from a .csv program. For example:

data[0] = '2014-01-31,46.83,48.55,46.80,48.03,3414400,48.03'

data[1] = '2014-01-30,47.47,48.11,47.29,48.00,2083900,48.00'

...etc.

I want to convert this into aa two-dimensional list such that:

newData[0][0] = '2014-01-31'
newData[0][0] = '2014-01-30'
newData[1][0] = '46.83'
newData[1][1] = '47.47'

...etc

That is, I want to split the strings at each , but when I tried using data.split(",") it doesn't want to do it because it's a list. Any ideas?

Answer 1

Apply str.split on the items of the list:

newData = [item.split(',') for item in data] 

Demo:

>>> data = ['2014-01-31,46.83,48.55,46.80,48.03,3414400,48.03', '2014-01-30,47.47,48.11,47.29,48.00,2083900,48.00']
>>> newData = [item.split(',') for item in data] 
>>> newData[0][0]
'2014-01-31'
>>> newData[1][0]
'2014-01-30'

As others have pointed out you should use csv module to read the data from a csv file, considering that the file contains:

2014-01-31,46.83,48.55,46.80,48.03,3414400,48.03
2014-01-30,47.47,48.11,47.29,48.00,2083900,48.00

This code will give the desired output:

import csv
with open('file.csv') as f:
    reader = csv.reader(f)
    data = list(reader)