When retrieving data from an external data file, the variable generated will be a list
.
>>>f=open("c:\\data\\ibm.csv","r") >>>data=f.readlines() >>>type(data) <class 'list'>
The first few lines of the input file are shown in the following lines of code. In Chapter 7, Visual Finance via Matplotlib, we will discuss how to download this input file from Yahoo! Finance.
>>>Date,Open,High,Low,Close,Volume,Adj Close 2013-07-26,196.59,197.37,195.00,197.35,2485100,197.35 2013-07-25,196.30,197.83,195.66,197.22,3014300,197.22 2013-07-24,195.95,197.30,195.86,196.61,2957900,196.61 2013-07-23,194.21,196.43,194.10,194.98,2863800,194.98 2013-07-22,193.40,195.79,193.28,194.09,3398000,194.09 2013-07-19,197.91,197.99,193.24,193.54,6997600,193.54
After we generate a variable called stock
, we can view its first two observations as follows:
>>>data[1] '2013-07-26,196.59,197.37,195.00,197.35,2485100,197.35\n' >>...