0.1. Help Ⓗ - JulTob/Python GitHub Wiki

🧭 When learning Python, two built-in tools matter a lot: dir() helps you discover what exists, and help() explains how to use it.

The dir function

📋 dir() returns a list of names that exist in some scope: functions, classes, variables, and other objects you can access.

📦 If you pass a module as an argument, dir(Module_Name) returns the names available inside that module.

👀 If you call dir() with no arguments, it lists what’s available in your current environment (the names you can use right now).

import sys

dir(sys)   # names available inside the sys module

['__breakpointhook__',
 '__displayhook__',
 '__doc__',
 '__excepthook__',
 '__interactivehook__',
 '__loader__',
...
 'stderr',
 'stdin',
 'stdlib_module_names',
 'stdout',
 'thread_info',
 'unraisablehook',
 'version',
 'version_info',
 'warnoptions']

dir()      # names available in the current environment

['In',
 'Out',
 ...
 'exit',
 'get_ipython',
 'quit',
 'sys']

The help function

📖 help() shows documentation for an object: what it does, how to call it, and what arguments it expects.

🔎 If you already know the function you want, you can ask Python directly for instructions like this:

help(max)

⚡ In IPython environments (like Jupyter), there’s a faster shortcut that shows the same idea in a more interactive way:

?max