Python modules
A Python module is a file containing Python definitions and statements. A module can define functions, classes, and variables. A module can also include runnable code. Grouping related code into a module makes the code easier to understand and use. It also makes the code logically organized.
The import statement - when the interpreter encounters an import statement, it imports the module. of the module is present in the search bath. A search bath is a list of directories that the interpreter searched for importing a module.
Example- create a simple calc.py module, in which we define two functions, one add and another subtract
def add (x, y):
return (x+y)
def subtract (x, y):
return (x-y)
Now, to import the module calc⋅py, we need to put the following command at the top of the script-
Syntax-import module
import calc
print (calc.add (10,2))
The from statement- Python's from statement is use to import specific attributes from a module without
importing the module as a whole.
Example - from math import sqrt, factorial
print (sqrt (16))
print (factorial (6))
Import all names- The * symbol used with the import statement is used to import all the names from a
module to a current namespace.
Syntax- from module_name import *
Example - from math import *
print (sqrt (16))
print (factorial (6))
Locating Python modules - when we import a module in Python, the interpreter searches for the module
in following manner-
First, it searches for the module in the current directory.
If the module isn't found in the current directory, Python then searches each directory in the shell variable PYTHONPATH.
If that also fails, Python checks the installation- dependent list of directories configured at the time Python is installed.
Directories list for Modules- sys.path is a built-in variable within the sys module. It contains a list of directories that the interpreter will search for the required module.
Example- import sys
print (sys.path)
Renaming the Python module- You can rename the module while importing it using the Keyword.
Syntax- import module_name as alias name
Example- import math as mt
print (mt.sqrt (16))
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