Explore

Now that you have a list of DataFrames, let's explore one of them, the planes dataset. Since you have a list of file names and a corresponding list of DataFrames, you can determine that the planes dataset is the third element in dfs.

Recall that you can call .value_counts() method to get a frequency count of the unique values in a column, and use .loc accessor to use boolean subsetting to filter the data. When combining multiple boolean expressions, the & and | operators stand for 'and', and 'or', respectively. Also, remember the boolean expressions need to be wrapped around a pair of parentheses.