PACKAGES:
========

COLLECTION OF MODULES IS CALLED AS "PACKAGE".

PYCHARM ==> DIRECTORY ==> PYTHON FILE (MODULE)
 DIRECTORY/FOLDER ==> PACKAGE

==> TREE TYPE OF HIERARCHY ==> PACKAGE

package ==> modules + __init__.py
=========================================

File Handling:
==============

Why files?
==========
to store the data permanently ==> files

==> Different types of files:
	1) Text files
		.txt
	2) Binary Files
		image files, audio files, video files etc.


How to open the file:
=====================
Syntax:
	file-pointer = open("file-name.txt", "mode-name")

File modes:
===========

w-mode ==> writing into file
=============================
==> open the file with 'w' mode:
	if the file is not available ==> 'w' ==> create the new file
	if the file is available ==> open that existing file by deleting all the content.

r-mode ==> reading-mode
=======================
==> we can use to open the existed file for reading purpose
==> no modification while r-mode.
==> if the file is not existed ==> r-mode can give the error.
	file not found error.

a-mode
======
==> a-mode can create the new file with specified name if it is not existed.
==> a-mode can also open the existing file for reading and writing both.
==> cannot overwrite the data in the file.

w+-mode
========
==> write + read

r+-mode
======
==> read + write
100-lines 
writing is possible after 100-lines

a+-mode
=======
append + read

x-mode:
=======
exclusive mode
==> writing purpose
==>like the w-mode, it can create the new file for only writing
but it can give "file existing error", when we can use this to open the existing file.

# File Modes

fp = open("abcd.txt","w")
fp1 = open("pqrst.txt","r")
fp2 = open("xyz.txt","a")
fp3 = open("pqrst.txt","a")
fp4 = open("abc.txt","w+")
# fp5 = open("pqrst.txt","w+")
fp5 = open("pqrst.txt","r+")
# fp6 = open("pqrst.txt","x")
fp6 = open("ravi.txt","x")