A value is one of the basic things a program works with, like a letter or a number. You can print values in Python. See what happens when you run the following code.
These values belong to different types: 17 is an integer, and “Hello World!” is a string, so called because it contains a “string” of letters. You can identify strings because they are enclosed in quotation marks.
Not surprisingly, strings belong to the type str and integers belong to the type int. Less obviously, numbers with a decimal point belong to a type called float, because these numbers are represented in a format called floating point.
When you type a large integer, you might be tempted to use commas between groups of three digits, as in 1,000,000. This is not a legal integer in Python, but it is legal:
Well, that’s probably not what you expected! Python interprets 1,000,000 as a comma-separated sequence of integers, which it prints with spaces between.
This is the first example we have seen of a semantic error: the code runs without producing an error message, but it doesn’t do the “right” thing.
