Table of Contents
The open() function opens the file (if possible) and returns the corresponding file object.
The syntax of open()
is:
open(file, mode='r', buffering=-1, encoding=None, errors=None, newline=None, closefd=True, opener=None)
1. open() Parameters
- file – path-like object (representing a file system path)
- mode (optional) – mode while opening a file. If not provided, it defaults to
'r'
(open for reading in text mode). Available file modes are:ModeDescription'r'
Open a file for reading. (default)'w'
Open a file for writing. Creates a new file if it does not exist or truncates the file if it exists.'x'
Open a file for exclusive creation. If the file already exists, the operation fails.'a'
Open for appending at the end of the file without truncating it. Creates a new file if it does not exist.'t'
Open in text mode. (default)'b'
Open in binary mode.'+'
Open a file for updating (reading and writing) - buffering (optional) – used for setting buffering policy
- encoding (optional) – the encoding format
- errors (optional) – string specifying how to handle encoding/decoding errors
- newline (optional) – how newlines mode works (available values:
None
,' '
,'\n'
,'r'
, and'\r\n'
- closefd (optional) – must be
True
(default); if given otherwise, an exception will be raised - opener (optional) – a custom opener; must return an open file descriptor
2. Return Value from open()
The open()
function returns a file object which can used to read, write and modify the file.
If the file is not found, it raises the FileNotFoundError
exception.
3. 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.
4. 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')
Python’s default encoding is ASCII. You can easily change it by passing the encoding
parameter.
f = open("path_to_file", mode = 'r', encoding='utf-8')
Recommended Reading: Python File Input/Output
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