Python open()

The open() python is used to open a file in the desired mode the user wants and returns the requested file object. Python allows the users to handle the files and supports the file handling. 

Here is the syntax for he open() in python: 

open (file, mode=’r’, buffering=-1, encoding=None, errors=None, newline=None, closefd=True, opener=None)

Source Code

open() Parameters

The open function parameters are given below:

1. file- this argument is used to represent the path of the file. This argument represents a path-like object. 
2. mode- this is an optional parameter. If this parameter is not given, it is in default in reading mode. The different modes of the files are:

1. -‘r’- it opens the file in the read-only mode. (this is the default mode for the files) 
2. -‘w’- this mode is for opening the file in the writing mode. When the file is opened in this mode, it will create a new file if the file does not exist. If the file exists, then the file will be truncated. 
3. -‘x’- This mode is used to open the file in the exclusive creation mode. If there is a file that is already existing, then the operation fails. 
4. -‘ a’- This mode is used to append the file without truncating it. This mode will create a new file if the file does not exist. 
5. -‘t ‘- This mode is used to opening the file in texting mode. (This is the default mode)
6. -‘b ‘- This mode is used to open the file in binary mode. 
7. -‘+ ‘- This mode is used to open the file in the update mode. (This is used for updating the file in the reading and writing.)
8. -buffering- This is an optional parameter. This argument is used to set the buffer policy. 
9. -encoding- This is an optional parameter. This argument is used to set the encoding format. 
10. -errors- this argument is also an optional parameter. This argument is used to specify how the string must handle the encoding and the decoding errors.
11. -newline- This optional parameter is used for a newline. The different modes available in this are- None, ‘ ‘, ‘\n’, ‘\r\n’, and ‘r’.
12. -closefd- This is an optional parameter. If the statement is untrue no exception is raised.
13. -opener- This is an optional parameter that is a custom opener. This argument should open a file descriptor.

Return Value from open()

The file object returned by the open() function can be used to read, write, and edit the file.

If the file cannot be found, the FileNotFoundError exception is thrown.

Example 1: How to open a file in Python?

                    

#opens the current directory's test.text file

a = open("test.txt")



#write the entire path of the file below

a=open("C:/Python33/README.txt")



                

Example 2: Providing mode to open()

                    

# opens the document in read-only mode

a = open("path_to_file", mode='r')



#opens the document in write-only mode

a = open("path_to_file", mode = 'w')



# the file is opened for writing 

a = open("path_to_file", mode = 'a')



The FileNotFoundError exception is thrown if the file cannot be found.



a = open("path_to_file", mode = 'r', encoding='utf-8')

                

What does open () do in Python?

The open() python is used to open a file in either the write mode or the read mode. We use the open() function with two arguments, the file name and the mode, whether to read or write, to return a file object.

What is the correct syntax of the open () function in Python?

The syntax of the open() is given below:

open(file, mode=’r’, buffering=-1, encoding=None, errors=None, newline=None, closefd=True, opener=None)

The syntax of the open() must be written correctly. If not, an error will be raised. 

How do I open a python file in Python?

To open a file in Python, the built-in function open() is used. This function is used to return a file object once the function is called. It is used to modify the file accordingly or read the file..We can also specify the mode of the file. 

Working of the open():

The open() is used to return a file in either the read or the write mode. The user uses the open() function with two arguments: the file name and the mode (read or write) to return a file object. Different modes are available for this are:

• “ r “, for reading the file
• “ r+ “,this mode if used for both reading and writing the file
• “ w “, for writing the file.
• “ a “, for appending the file.

Example program:

                    

file1 = open("myfile.txt")



# Reading from file

print(file1.read())

  

file1.close()



Output:

Welcome to Toppr!!

                

How do I open a python path?

The open() is used to open a specific file path using the python programming language. This function requires it to provide the full path of the file. There are 7 access modes for the open() in Python.