A module is a python file with .py extension.

import statement

One module can refer to the code written inside another module using the import statement.

We have two files - vaccines.py and travel.py - in the sme directory.

vaccine_list = ['Pfizer', 'AstraZeneca', 'Moderna']

effectiveness = {'Pfizer': 0.9, 'AstraZeneca': 0.85, 'Moderna': 0.95}

import vaccines

def travelPermit(vaccine):
    if vaccine in vaccines.vaccine_list:
        print("You can travel to Europe.")
    else:
        print("You can't travel to Europe.")

The travel module needs to refer to the code in the vaccines module. Therefore, on line 1, we import the vaccines module. This makes everything inside the vaccines module available to our program in the travel module.

To use any code from the vaccines module, we must qualify it with the name of the module. On line 4, we access the vaccine_list variable by tacking vaccines. before its name.

Import a module with another name

We can import a module with another name using an alias.

For example, we can import the vaccines module under the alias vac. (you can choose any name you want.)

import vaccines as vac

def travelPermit(vaccine):
    if vaccine in vac.vaccine_list:
        print("You can travel to Europe.")
    else:
        print("You can't travel to Europe.")


result = travelPermit("Covaxin")

print(result)
# You can't travel to Europe.

Import only a part of a module

In the code example above, we imported the whole vaccines module, which contains two variables: vaccine_list & effectiveness. Our program in the travel module needs access only to the vaccine_list variable. Therefore, we can choose to specifically import the vaccine_list variable instead of the whole vaccines module as shown below:

from vaccines import vaccine_list

def travelPermit(vaccine):
    if vaccine in vaccine_list:
        print("You can travel to Europe.")
    else:
        print("You can't travel to Europe.")


result = travelPermit("Moderna")

print(result)
# You can travel to Europe.