pandas keeps a table in a DataFrame: rows of records, named columns, and an index on the left that labels each row. Almost every analysis starts the same way, by reading a file into one:
df = pd.read_csv("sales.csv")
Before you calculate anything, look at what you loaded. df.head() shows the first five rows and df.tail() the last five; both take a number, like df.head(10). df.shape tells you how many rows and columns there are. It has no parentheses because it's an attribute, not a method.
You'll work in a Jupyter-style notebook. Type in a cell and press Shift + Enter to run it. Whatever the last line of the cell evaluates to appears below it, next to Out[n]. The data in this course comes from Juniper Lane, a made-up homeware shop with four regions, a web shop and physical stores.