Python Modules :

are pre-written lines of code as functions pre-stored in python programming language ready to reuse by python programmers in python editor but before using, we should import them firstly.

We called them python libraries especially the the huge lines of code.

Examples:

pandas

numpy

matplotlib

random

We can create our modules:

We want to use the check_even_or_odd() function we defined it earlier in another Python script.

Example:

def even_or_odd(n):

if n % 2 == 0:

print('This number is even')

else:

print('This number is odd')

So Firstly we save the last as check.py on our desktop, then we will import this module in new python.py:

We will proceed as follow:
>>>import check

>>>answer = check.even_or_odd(3)

>>>print(answer)

Result: This number is odd

>>>answer = check.even_or_odd(6)

>>>print(answer)

Result: This number is even

Open files in Python:

We should open files in python before we can read or write , so we could

use open function in python to open files:

>>>data_file = open(“file_name”, “open mode”)

open modes:

“r”: default read only mode.

“rb”: Binary read only mode.

“r+”:default read & write mode.

“rb+”: Binary read & write mode.

“w”:default write only mode.

“w”: default write only mode.

“wb”: Binary write only mode.

“w+”:default read & write mode.

“wb+”: Binary read & write mode.

“b”:Binary mode.

“a”: append read & write create the file if the file not exist mode.

“x”: create the file if the file not exist mode.

file.read():

We use this method to read all the file or lines of file

>>>f = open(“file_name”, “open mode”)

>>>f = open(“file_name.txt”, “r”)

>>>print(f.read( ))

>>> print(f.read(2 ))

>>> print(f.read( 6))

>>> print(f.read(10))

file.readline():

We use this method to read the file line by line.

>>>f = open(“file_name”, “open mode”)

>>>f = open(“file_name.txt”, “r”)

>>>print(f.readline( ))

Loop with Open File Function:

We use loop with Open File Function to read our file :

>>>f = open(“file_name”, “open mode”)

>>>f = open(“file_name.txt”, “r”)

>>> for line in file:

print(line)

file.close():

We use this method to close the file which is agood practice to avoid system Memory blocking by the files we opened .

>>>f = open(“file_name”, “open mode”)

>>>f = open(“file_name.txt”, “r”)

>>>print(f.readline( ))

>>>f.close( )

File Removing:

We use this method to read the file line by line.

>>>data_file = open(“file_name”, “open mode”)

>>>data_file = open(“file_name.txt”, “r”)

>>>print(f.readline( ))

>>>f.close

>>>import os

>>> os.remove(“file_name.txt”)