Data, Data Everywhere¶
“In God we trust, all others must bring data.” - W. Edwards Deming
How data is stored¶
Data streams itself right from when the gates of a stock exchange open to when it closes. Such data contains vital information that is archived each day. Some of the many types of information recieved after trading hours are - opening price, closing price, volumne of shares, highest price, lowest price, etc. for each enterprise.
bulbea helps you access such information (both - archived and the latest). Simply create a Share with a known source and ticker as follows:
>>> import bulbea as bb
>>> share = bb.Share(source = 'YAHOO', ticker = 'GOOGL')
>>> share.data
Open High Low Close Volume Adjusted Close
Date
2004-08-19 99.999999 104.059999 95.959998 100.339998 44659000.0 50.220219
2004-08-20 101.010005 109.079998 100.500002 108.310002 22834300.0 54.209210
2004-08-23 110.750003 113.479998 109.049999 109.399998 18256100.0 54.754754
...
Data is accessed through the Quandl API stored remotely at sources in the form of CSV (Comma-Seperated Values) files. Information retrieved from such a CSV file is then wrapped around a pandas.DataFrame object.
Comma, Seperated, Value?¶
CSV files store tabular data in simple plain text (well, fits the need). Each row containing values associated to each attribute of a table are stored in a single line, where each value is seperated by a delimiter, you guessed it right, a comma. For instance, a data set containing the weight (in kilograms) and height (in inches) of members of my family would look something like the following:
weight,height
87,6.2
51,5.8
68,5.9
...
Almost always, the top-most line (also called as the header) should denote the attribute names seperated by the delimiter.
You can save a share object in a CSV format as follows:
>>> share.save()
By default, the save method saves a share as a CSV file in the working directory with a file name of the format - <source>_<ticker>_<start>_<end>.csv. You could also name the file anything you like as follows:
>>> share.save(filename = 'mycsvfile.csv')
