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Python open()

The built-in function open() is a good method for working with files. This method will check whether the file exists in the specified path, if yes it will return the file object otherwise it returns an error.

open(file, mode='r', buffering=-1, encoding=None, errors=None, newline=None, closefd=True, opener=None) #where file specifies the path

open() Parameters:

Takes 8 parameters in this one is required all the remaining are optional. In this mode type have many options(r: read, w: write, x: exclusive creation, a: appending, t: text mode, b: binary mode,+:updating(read,write))

Parameter Description Required / Optional
file  path-like object Required
mode  mode (optional) - mode while opening a file. If not provided, it defaults to 'r' optional
buffering used for setting buffering policy optional
encoding the encoding format optional
errors a string specifying how to handle encoding/decoding errors optional
newline how newlines mode works(available values: None, ' ', '\n', 'r', and '\r\n') optional
closefd must be True (default); if given otherwise, an exception will be raised optional
opener a custom opener; must return an open file descriptor optional

open() Return Value

If the file exists in the specified path it will return a file object which can be used to read, write and modify. If the file does not exist, it raises the FileNotFoundError exception.

Input Return Value
 if file exist file object

Examples of open() method in Python

Example 1: How to open a file in Python?

# opens test.text file of the current directory
f = open("test.txt")

# specifying the full path
f = open("C:/Python33/README.txt")


Since the mode is omitted, the file is opened in 'r' mode; opens for reading.

Example 2: Providing mode to open()

# opens the file in reading mode
f = open("path_to_file", mode='r')

# opens the file in writing mode 
f = open("path_to_file", mode = 'w')

# opens for writing to the end 
f = open("path_to_file", mode = 'a')


Open a file in read,write and append mode.