"Many people, including the author, even use interactive Python as their desktop calculator."
"When you use Python interactively, the special variable _ holds the result of the last operation."
"A newline terminates each statement. However, you can use a semicolon to separate statements on the same line."
"Although str() and repr() both create strings, their output is usually slightly different. str() produces the output that you get when you use the print statement, whereas repr() creates a string that you type into a program to exactly represent the value of an object."
"The format() function is used to convert a value to a string with a specific formatting applied."
"The expression [float(line) for line in lines] constructs a new list by looping over all the strings in the list lines and applying the function float() to each element."