In this book, you will find a number of text styles that distinguish between different kinds of information. Here are some examples of these styles and an explanation of their meaning.

Code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles are shown as follows: "It also enables us to install and compile new R packages directly from the R console using the install.packages() command."

A block of code is set as follows:

    if (test expression) 
    { 
      Statement upon condition is true 
    }

Any command-line input or output is written as follows:

pip3 install -upgrade pip 
pip3 install jupyter

New terms and important words are shown in bold. Words that you see on the screen, for example, in menus or dialog boxes, appear in the text like this: "To start a new R Notebook, click on right hand side New tab and select R kernel as shown in Figure 1.7."