How to View Python Package Documentation
You can use the
doc() function whenever needed to get quick help. However, you have a better way to study the packages and libraries located in the Python path — the Python Package Documentation. This feature often appears as Package Docs in the Python folder on your system. It’s also referred to as Pydoc. Whatever you call it, the Python Package Documentation makes life a lot easier for developers.
Opening the Pydoc application
Pydoc is just another Python application. It actually appears in the
\Python36\Lib directory of your system as
pydoc.py. As with any other
.py file, you can open this one with Notebook and study how it works. You can start it by using the Python 3.6 Module Docs shortcut that appears in the Python 3.6 folder on your system or by using a command at the Anaconda Prompt.
You can use Pydoc in both graphical and textual mode. When opening an Anaconda Prompt, you can provide a keyword, such as JSON, and Pydoc displays textual help. Using the -k command-line switch, followed by a keyword such as if, lets you display a list of places where specific keywords appear. To actually start the server, you type Pydoc -b and press Enter. If you need to use a specific port for your browser, add the -p command-line switch with a port number.
The graphical mode of the Pydoc application creates a localized server that works with your browser to display information about the Python packages and libraries. So when you start this application, you see a command (terminal) window open.
As with any server, your system may prompt you for permissions. For example, you may see a warning from your firewall telling you that Pydoc is attempting to access the local system. You need to give Pydoc permission to work with the system so that you can see the information it provides. Any virus detection that you have installed may need permission to let Pydoc continue as well. Some platforms, such as Windows, may require an elevation in privileges to run Pydoc.
Normally, the server automatically opens a new browser window for you. This window contains links to the various packages that are contained on your system, including any custom packages you create and include in the Python path. To see information about any package, you can simply click its link.
The Anaconda Prompt provides you with two commands to control the server. You simply type the letter associated with the command and press Enter to activate it. Here are the two commands:
b: Starts a new copy of the default browser with the index page loaded.
q: Stops the server.
When you’re done browsing the help information, make sure that you stop the server by typing q and pressing Enter at the command prompt. Stopping the server frees any resources it uses and closes any holes you made in your firewall to accommodate Pydoc.
Using the quick-access links
Near the top of the web page, you see three links. These links provide quick access to the site features. The browser always begins at the Module Index. If you need to return to this page, simply click the Module Index link.
The Topics link takes you to the page shown below. This page contains links for essential Python topics. For example, if you want to know more about Boolean values, click the BOOLEAN link. The page you see next describes how Boolean values work in Python. At the bottom of the page are related links that lead to pages that contain additional helpful information.
The Keywords link takes you to the page below. What you see is a list of the keywords that Python supports. For example, if you want to know more about creating
for loops, you click the for link.
Typing a search term
The pages also include two text boxes near the top. The first has a Get button next to it and the second has a Search button next to it. When you type a search term in the first text box and click Get, you see the documentation for that particular package or attribute. This is what you see when you type print and click Get.
When you type a search term in the second text box and click Search, you see all the topics that could relate to that search term. The image below shows typical results when you type print and click Search. In this case, you click a link, such as calendar, to see additional information.
Viewing the results
The results you get when you view a page depends on the topic. Some topics are brief. However, other topics are extensive. For example, if you were to click the calendar link, you would see a significant amount of information.
In this particular case, you see related package information, error information, functions, data, and all sorts of additional information about the calendar printing functions. The amount of information you see depends partly on the complexity of the topic and partly on the amount of information the developer provided with the package. For example, if you were to select BPPD_11_Packages from the Package Index page, you would see only a list of functions and no documentation at all.