Files in Python :

Python provides basic functions and methods necessary to manipulate files by default.
Most of the file manipulation can be done using a file object.

Before you can read or write a file, you have to open it using Python's built-in open() function. This function creates a file object, which would be utilized to call other support methods associated with it. 

file_obj = open ( " file_name.txt " , " access_mode " )

Access Modes:

r = Read only
r+ = Read and Write
w = Write only
w+ = Write and Read
a = Append
a+ = Append and Read

Simple program to open a file:

fo = open ( " foo.txt " , " w " ) 
print ( " Name of the file : " , fo.name ) 
print ( " Closed or not : ", fo.closed ) 
print ( " Opening mode : ", fo.mode )
fo.close() 

Output:

Name of the file: foo.txt 
Closed or not : False
Opening mode : w


close() method

The close() method of a file object flushes any unwritten information and closes the file object, after which no more writing can be done.

write() method

The write() method writes any string to an open file

fo = open ( " foo.txt " , " w ") 
fo.write ( " Python is a great language.\nYeah its great!!\n " )
fo.close()

Output:

Python is a great language. 
Yeah its great!!


read() method

The read() method reads a string from an open file. 

fileObject.read([count]) 

Here, passed parameter is the number of bytes to be read from the opened file. This method starts reading from the beginning of the file and if count is missing, then it tries to read as much as possible, maybe until the end of file. 

fo = open ( " foo.txt " , " r+ " ) 
str = fo.read ( 10 ) 
print ( " Read String is : ", str )
fo.close()

Output

Read String is : Python is