17.modules

Modules

A file containing a set of functions you want to include in your application.

Create a Module

To create a module just save the code you want in a file with the file extension .py

Example

Save this code in a file named mymodule.py

def greeting(name):
  print("Hello, " + name)

Use a module

Now we can use the module we just created, by using the import statement

Example

Import the module named mymodule, and call the greeting function

import mymodule
mymodule.greeting("Bhavya")

Variables in module

The module can contain functions, as already described, but also variables of all types (arrays, dictionaries, objects etc)

Example

Save this code in the file mymodule.py

person = {
  "name": "Bhavya",
  "age": 29,
  "country": "India"
}

Import the module named mymodule, and access the person dictionary

import mymodule

a = mymodule.person1["name"]
print(a)

Output:
Bhavya

Re-naming a module

We can create an alias when you import a module, by using the as keyword

Example

Create an alias for mymodule called mx

import mymodule as mx

a = mx.person1["age"]
print(a)

Built-in Modules

There are several built-in modules in Python, which we can import whenever you like.

Example

Import and use the platform module

import platform

x = platform.system()
print(x)

Output:
Linux

Using the dir() function

The dir() function lists all the function names or variable names in a module.

Example

import platform

x = dir(platform)
print(x)

Import From Module

We can choose to import only parts from a module, by using the from keyword.

Example

mymodule.py

def greeting(name):
  print("Hello, " + name)

person = {
  "name": "Bhavya",
  "age": 29,
  "country": "India"
}

Import only the person dictionary from the module.

from mymodule import person1

print (person["name"])

Output:
Bhavya