8.7: User Created Package

This activity is correlated to Assignment 3.  In your class folder we want you to create a subfolder Sandbox and in it we want you to create a file called my_script.py and subfolder called My_toolbox. and 

So the directory hierarchy looks like this, where the folders start with a captial letter and the files all end with .py

• Sandbox
  • my_script.py
  • Tools
    • __init.py__
    • my_tool_box.py

Python files

my_script.py

This file is in the Sandbox and located next to the Tools directory (folder).  It will call functions from a module within the Tools package.  We will use the follow code for this.

#Script 1: my_script.py
from Tools import my_toolbox as mtb
num1=float(input("Enter first number: "))
num2=float(input("Enter second number: "))
value=mtb.addition(num1,num2)
print(f"The sum of {num1} and {num2} is {value}.")
print(f"the type for the variable now is {type(value)}.\n")

now = mtb.current_date()
print(f"The current date is {now}.")
print(f"the type for the variable now is {type(now)}.")

 

__init__.py

Place this file in the Tools directory. The __init__.py (and those are two underscores) is used to mark a directory as a Python Package and when present in a folder, python treats the folder as a package, which means it can be imported into another program as a module.  Right now we are going to keep the __init__.py file empty, but for example, if the files in the package had dependencies on other packages, like the time module, they could be set up in the __init__.py  file

 

my_toolbox.py

Place this file in the tools directory.  It will serve as a module where you can create functions (tools) that can be called from other programs. 

#Script 2: my_toolbox.py
'''This package contains functions that can be called by other programs'''

def addition(num1,num2):
    the_sum=num1+num2
    return(the_sum)

def current_date():
    import datetime
    today=datetime.date.today()
    return(today)

Note, there are two functions in the second script; addition and current_time. The addition has two arguments that must be submitted when the first script calls it (num1 and num2 are passed from script 1 to script 2 as arguments) and it returns one value, the sum.  The second function (current_time) has no parameters, and so you pass it nothing when you call it, but it returns the variable "today", which you assign to the variable "now" in the calling program