line.split()

The `split()` method is a built-in function in Python that is used to split a string into a list of substrings based on a specified delimiter.

When called on a string variable named `line`, the `split()` method will split the string into substrings separated by whitespace (spaces, tabs, and newlines) by default. The resulting substrings will be returned as a list.

Example:

line = "The quick brown fox"
words = line.split()
print(words)

Output:

['The', 'quick', 'brown', 'fox']

In this example, the `split()` method is called on the string variable `line`, which contains the sentence "The quick brown fox". Since no delimiter is specified, the method splits the string into a list of words, which are stored in the `words` variable. The resulting list contains the words "The", "quick", "brown", and "fox".