Numerical Computing with Python

How it works...

The .loc indexing operator is used to select and assign data based on the row and column labels. The first value passed to it represents the row label. In step 2, names.loc[4] refers to the row with a label equal to the integer 4. This label does not currently exist in the DataFrame. The assignment statement creates a new row with data provided by the list. As was mentioned in the recipe, this operation modifies the names DataFrame itself. If there was a previously existing row with a label equal to the integer 4, this command would have written over it. This modification in-place makes this indexing operator riskier to use than the append method, which never modifies the original calling DataFrame.

Any valid label may be ...