LANGUAGE » PYTHON

File

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Reference:docs.python.org

Usage ​

TIP

If using Python 3.4+, prefer using pathlib instead.

Open file and return a corresponding file object.

python
open(path, mode, encoding='utf-8')

Obs: If dealing with text file, setting the encoding is recommended.

ModeDescription
rOpen for reading (default).
wOpen for writing, truncating the file first.
xOpen for exclusive creation, failing if the file already exists.
aOpen for writing, appending to the end of the file if it exists.
bBinary mode.
tText mode (default).
+Open for updating (reading and writing).

It may also be useful to check out the contents of package > os for system wide operations.

Examples ​

Write an audio file:

python
with open('sound.mp3', 'wb') as audio_file:
    audio_file.write(data)

Read a text file:

python
with open(os.path.join('path', 'to', 'file.txt'), 'r', encoding='utf-8') as f:
    all_text = f.read()
    lines_list = f.readlines()  # Keeps \n at the end
    each_line_as_element_in_list = f.readlines()

Append some text to a text file:

python
with open('existing_file.txt', 'a', encoding='utf-8') as f:
    f.write('Hello World')

Read only the last line of a file:

python
import os

with open('filename.txt', 'rb') as f:
    try:  # catch OSError in case of a one line file
        f.seek(-2, os.SEEK_END)
        while f.read(1) != b'\n':
            f.seek(-2, os.SEEK_CUR)
    except OSError:
        f.seek(0)
    last_line = f.readline().decode()