4.8 Using IPython Tab Completion for Discovery

  • View a module’s documentation in IPython interactive mode via tab completion.
  • After you type a portion of an identifier and press Tab, IPython completes the identifier for you or provides a list of identifiers that begin with what you’ve typed so far.
In [1]:
import math
In [ ]:
# press <Tab> after ma  
ma

Viewing Identifiers in a Module

  • To view a list of identifiers defined in a module, type the module’s name and a dot (.), then press Tab:
In [ ]:
# press <Tab> after the dot   
math.
  • Python does not have constants, although many objects in Python are immutable (nonmodifiable).
  • Even though pi and e are real-world constants, you must not assign new values to them, because that would change their values.
  • To help distinguish constants from other variables, the style guide recommends naming your custom constants with all capital letters.

Using the Currently Highlighted Function

  • As you navigate through the identifiers, if you wish to use a currently highlighted function, simply start typing its arguments in parentheses.
  • If you need more information about the currently highlighted item, you can view its docstring by typing a question mark (?) following the name and pressing Enter to view the help documentation.
In [2]:
math.fabs?

Signature: math.fabs(x, /)
Docstring: Return the absolute value of the float x.
Type:      builtin_function_or_method
  • The builtin_function_or_method shown above indicates that fabs is part of a Python Standard Library module.
  • Such modules are considered to be built into Python.
  • In this case, fabs is a built-in function from the math module.

©1992–2020 by Pearson Education, Inc. All Rights Reserved. This content is based on Chapter 4 of the book Intro to Python for Computer Science and Data Science: Learning to Program with AI, Big Data and the Cloud.

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