Explanation of built-in functions

[justindlc]

This is in fulfillment of instructor training checkout step 1.

I think for the "Built-in Python functions" portion (https://swcarpentry.github.io/python-novice-inflammation/01-intro/index.html), it would help learners to include an explanation of the role of parentheses in functions. It might not be necessary to go into invoking functions without parentheses, but it might help newcomers to understand that python functions are usually invoked with, for example, print().

The explanation for the introduction of this section could be as short as:

Most functions in Python are used with parentheses immediately after a word, like function(). Any items included inside of the parentheses are called arguments and tell the function what to do. So if we use print("Test.") then Test. is the argument used in this print function.

[jamesacris]

I may be misunderstanding, but as far as I can see there is already an explanation of parentheses in the built-in functions lesson:

When we want to make use of a function, referred to as calling the function, we follow its name by parentheses. The parentheses are important: if you leave them off, the function doesn’t actually run! Sometimes you will include values or variables inside the parentheses for the function to use. In the case of print, we use the parentheses to tell the function what value we want to display. We will learn more about how functions work and how to create our own in later episodes.