Running and Quitting

Overview

Teaching: 5 min
Exercises: 0 min

Questions

• How can I run Python programs?

Objectives

• Run the ipython command prompt.

• Write a python file.

• Execute a python file, both in the script and out.

Running an ipython session

• Ipython is a common and very powerful way to test small pieces of python code.

• It is also the basis for many other python tools such as Jupyter and is emulated in many other environments, such as IDEs.

• To run ipython, first enter your terminal, then simply type:

$ ipython

and you should see a prompt like this, but more colorful:

Python 3.6.6 (default, Sep 19 2018, 12:51:03)
Type 'copyright', 'credits' or 'license' for more information
IPython 6.5.0 -- An enhanced Interactive Python. Type '?' for help. 

In [1]: 

• To exit the ipython, type exit and hit enter.

Creating an executable python file

• Like shell scripts, you can save your code in a file

• Now create a directory somewhere called swc-python

• Open up atom, either by clicking on the icon or typing atom in your terminal.

• Now, in your terminal, create a new directory under swc-python called scripts.

• In atom, create a new file, and then save it as test.py in the scripts directory.

• This is a python script file. Note that .py indicats a python file, but this is convention, not requirement.

• In your terminal, navigate to the scripts directory.

• You can now run the script using

  $ python test.py
  

• Similarly, if you start up ipython again, from within ipython you can do

  In [1]: run test.py
  

  which will run all the code in test.py as though entered into ipython.

Key Points

• Python scripts are plain text files.

• Use the ipython for editing and running Python.