Splitting this CSV file into a list

Question

So I want to read in a csv file in Python3 and split it into a list. Where each index[0,1, ..., onwards] relates to each value separated by comma. This is my csv file:

2017-04-1,14.9,30.1,0,8.2,10.8,NE,33,11:55,20.3,51,0,E,11,1023.9,29.5,25,0,ENE,7,1020.3
,2017-04-2,17.4,31.6,0,8.0,10.9,NE,35,08:56,23.5,34,0,NE,17,1021.4,30.7,20,0,SE,9,1018.6
2017-04-3,12.1,31.8,0,6.8,10.8,SSW,33,15:14,23.1,39,0,SSE,6,1022.7,29.3,34,0,SSW,19,1020.8
,2017-04-4,15.4,30.4,0,7.0,10.7,E,28,03:01,19.8,64,0,ESE,11,1024.9,29.7,29,0,S,9,1020.3
,2017-04-5,12.3,30.4,0,5.2,10.6,S,19,13:10,21.7,55,0,NE,6,1018.2,27.7,37,0,WSW,11,1013.5
,2017-04-6,13.7,24.4,0,5.2,8.1,SW,43,16:16,17.1,94,7,NE,2,1013.1,22.8,63,3,SSW,20,1011.7
,2017-04-7,14.8,22.3,0,5.4,8.9,SSE,35,06:26,16.4,56,5,SSE,17,1023.6,21.3,33,3,SSE,4,1021.6
,2017-04-8,8.7,23.6,0,5.0,10.5,SW,33,15:41,16.0,58,0,SE,7,1027.6,22.1,44,0,SW,17,1024.5
,2017-04-9,11.1,27.4,0,4.8,10.4,ESE,24,10:30,18.1,56,0,ENE,13,1027.4,26.8,26,0,NE,9,1023.1
,2017-04-10,10.0,30.1,0,5.6,10.4,SSW,24,16:38,19.3,51,4,E,9,1022.7,30.0,20,1,E,6,1018.4
,2017-04-11,13.1,28.1,0,6.6,10.5,SW,28,15:02,21.8,38,0,NE,9,1016.6,26.6,35,0,SW,13,1015.7
,2017-04-12,10.6,23.8,0,5.2,9.7,SW,35,16:19,17.4,69,6,ENE,9,1021.5,23.0,52,1,SW,15,1019.9
,2017-04-13,12.9,26.8,0,4.2,10.4,SSW,31,15:56,19.9,64,1,ESE,11,1024.3,25.5,49,1,SW,15,1020.1
,2017-04-14,12.8,29.0,0,5.8,6.2,SW,22,15:43,18.1,73,4,SSE,2,1019.3,27.6,42,5,SSW,11,1015.4
,2017-04-15,14.8,29.3,0,4.0,7.3,SSE,31,22:03,18.5,73,6,S,11,1015.7,28.2,38,7,SE,9,1011.7
,2017-04-16,17.2,25.1,0,5.4,7.0,SSE,35,00:43,18.8,66,4,ESE,11,1014.6,24.4,54,5,SW,11,1011.6
,2017-04-17,15.4,21.8,0,5.0,2.5,SSW,24,07:56,17.8,74,5,S,13,1015.3,21.4,59,8,SSW,11,1013.2
,2017-04-18,15.3,25.0,0,4.0,8.0,SSW,31,19:02,19.7,72,6,SSE,9,1013.0,22.8,63,1,SW,15,1010.4

Currently when I read it in, each element is being split at the end of the line. So if I accessed index[0] this would be the output.

2017-04-1,14.9,30.1,0,8.2,10.8,NE,33,11:55,20.3,51,0,E,11,1023.9,29.5,25,0,ENE,7,1020.3

What I need to understand is how to split the csv so that if I access index[0], I will be given 2017-04-1. And index[1] would give the next value after the comma.

Here is my code at the moment.

import matplotlib.pyplot as plt
# Opening and reading files
weatherdata = open('weather.csv', encoding='latin1')
data = weatherdata.readlines()

Encoding is required to be in latin one because it needs to be able to handle degree symbols.

Thanks for the guidance.

Answer 1

You have already read all lines into data:

weatherdata = open('weather.csv')
data = weatherdata.readlines()
data

data will be a string list:

['2017-04-1,14.9,30.1,0,8.2,10.8,NE,33,11:55,20.3,51,0,E,11,1023.9,29.5,25,0,ENE,7,1020.3\n',
 '2017-04-2,17.4,31.6,0,8.0,10.9,NE,35,08:56,23.5,34,0,NE,17,1021.4,30.7,20,0,SE,9,1018.6 \n',
 '2017-04-3,12.1,31.8,0,6.8,10.8,SSW,33,15:14,23.1,39,0,SSE,6,1022.7,29.3,34,0,SSW,19,1020.8\n',
 '2017-04-4,15.4,30.4,0,7.0,10.7,E,28,03:01,19.8,64,0,ESE,11,1024.9,29.7,29,0,S,9,1020.3\n',
 '2017-04-5,12.3,30.4,0,5.2,10.6,S,19,13:10,21.7,55,0,NE,6,1018.2,27.7,37,0,WSW,11,1013.5\n',
 '2017-04-6,13.7,24.4,0,5.2,8.1,SW,43,16:16,17.1,94,7,NE,2,1013.1,22.8,63,3,SSW,20,1011.7\n',
 '2017-04-7,14.8,22.3,0,5.4,8.9,SSE,35,06:26,16.4,56,5,SSE,17,1023.6,21.3,33,3,SSE,4,1021.6\n',
 '2017-04-8,8.7,23.6,0,5.0,10.5,SW,33,15:41,16.0,58,0,SE,7,1027.6,22.1,44,0,SW,17,1024.5\n',
 '2017-04-9,11.1,27.4,0,4.8,10.4,ESE,24,10:30,18.1,56,0,ENE,13,1027.4,26.8,26,0,NE,9,1023.1\n',
 '2017-04-10,10.0,30.1,0,5.6,10.4,SSW,24,16:38,19.3,51,4,E,9,1022.7,30.0,20,1,E,6,1018.4\n',
 '2017-04-11,13.1,28.1,0,6.6,10.5,SW,28,15:02,21.8,38,0,NE,9,1016.6,26.6,35,0,SW,13,1015.7\n',
 '2017-04-12,10.6,23.8,0,5.2,9.7,SW,35,16:19,17.4,69,6,ENE,9,1021.5,23.0,52,1,SW,15,1019.9\n',
 '2017-04-13,12.9,26.8,0,4.2,10.4,SSW,31,15:56,19.9,64,1,ESE,11,1024.3,25.5,49,1,SW,15,1020.1\n',
 '2017-04-14,12.8,29.0,0,5.8,6.2,SW,22,15:43,18.1,73,4,SSE,2,1019.3,27.6,42,5,SSW,11,1015.4\n',
 '2017-04-15,14.8,29.3,0,4.0,7.3,SSE,31,22:03,18.5,73,6,S,11,1015.7,28.2,38,7,SE,9,1011.7\n',
 '2017-04-16,17.2,25.1,0,5.4,7.0,SSE,35,00:43,18.8,66,4,ESE,11,1014.6,24.4,54,5,SW,11,1011.6\n',
 '2017-04-17,15.4,21.8,0,5.0,2.5,SSW,24,07:56,17.8,74,5,S,13,1015.3,21.4,59,8,SSW,11,1013.2\n',
 '2017-04-18,15.3,25.0,0,4.0,8.0,SSW,31,19:02,19.7,72,6,SSE,9,1013.0,22.8,63,1,SW,15,1010.4']

Then use data[0].split(',')[0], it will give you:

'2017-04-1'

and data[0].split(',')[1], will be:

'14.9'

and so on.

Answer 2

Or you can use pandas and it does it for you,Pandas is very useful to read dataset and manipulate them,it reads the data all at once and you can get different columns after reading them

import pandas as pd
df = pd.read_csv('weather.csv')
df.column[0]# this will get the first column

Answer 3

Simply read and then split:

weatherdata = open('weather.csv')
data = [line.split(',') for line in weatherdata.read().splitlines()]