Python Module
A module is a file consisting of Python code. A module can
define functions, classes, and variables. A module can also include
runnable code.
Modules are used to categorize Python code into smaller parts.
A module is simply a Python file, where classes, functions, and
variables are defined. Grouping similar code into a single file
makes it easy to access. Have a look at the below example.
Module Advantage
Reusability: Modules let programmers save source code in
files permanently & hence the codes in module files are
persistent. Module codes can rerun as many times as required.
Categorization: Similar type of attributes can be placed in one
module.
Import Statement
Programmers can use any Python source code as a module by
implementing an 'import' statement in another Python program or
Python file.
Syntax
Import file1,file2..filen
When the interpreter encounters an import statement, it imports
the module if the module is present in the search path. A search
path is a list of directories that the interpreter searches before
importing a module.
Example:
add.py file
def add1(a,b):
print (a+b)
Save this code in the file by the name add.py. Now import this
file in another file or code.
Example:
import add
add.add1(10,20)
add.add1(20,30)
Output:
Importing Multiple Modules Example
In this example, we create three python modules files namely
add.py, sub.py, div.py, and python file main.py for importing all
three files.
add.py file
def add1(a,b):
sub.py file
def sub1(a,b):
print (a-b)
div.py file
def div1(a,b):
print (a/b)
Now import all three modules file in the following example.
main.py file
import add,sub,div
add.add1(20,10)
sub.sub1(20,10)
div.div1(20,10)
Output:
from.. import statement
from..import statement is used to import particular attribute
from a module. In case you do not want the whole of the module to be
imported then you can use it from the import statement.
In this example, we create one python modules file namely
math.py and python file main.py for import attributes from another
python file.
math.py file
def add1(a,b):
print (a+b)
def sub1(a,b):
print (a-b)
def div1(a,b):
print (a/b)
main.py file
from math import add1,sub1,div1
add1(20,10)
sub1(20,10)
div1(20,10)
Output:
import whole module
we can import the whole of the module using "from main import *"
Example:
from math import *
add1(20,10)
sub1(20,10)
div1(20,10)
Output:
Packages in Python
A package is a hierarchical file directory structure that defines
a single Python application environment that consists of modules
and sub-packages.
To create a package in Python, we need to follow these three
simple steps:
- First, we create a directory and give it a package name,
preferably related to its operation.
- Then we put the classes and the required functions in it.
- Finally, we create an __init__.py file inside the directory, to let
Python knows that the directory is a package
Example
1.First Create a directory with name as cal.
2.Then create two modules add.py and sub.py in cal direct.
add.py file
def add(a,b):
print (a+b)
sub.py file
def sub(a,b):
print (a-b)
3.Create __init__.py file in cal direct.
from add import add
from sub import sub
4.Now import this package and run it
import cal
cal.add(20,10)
cal.sub(20,10)
Output:
