[python] Working With Files

1. Reading a File

To read the entire content of a file:

with open('example.txt', 'r') as file:
    content = file.read()
    print(content)

2. Writing to a File

To write text to a file, overwriting existing content:

with open('example.txt', 'w') as file:
    file.write('Hello, Python!')

3. Appending to a File

To add text to the end of an existing file:

with open('example.txt', 'a') as file:
    file.write('\nAppend this line.')

4. Reading Lines into a List

To read a file line by line into a list:

with open('example.txt', 'r') as file:
    lines = file.readlines()
    print(lines)

5. Iterating Over Each Line in a File

To process each line in a file:

with open('example.txt', 'r') as file:
    for line in file:
        print(line.strip())

6. Checking If a File Exists

To check if a file exists before performing file operations:

import os
if os.path.exists('example.txt'):
    print('File exists.')
else:
    print('File does not exist.')

7. Writing Lists to a File

To write each element of a list to a new line in a file:

lines = ['First line', 'Second line', 'Third line']
with open('example.txt', 'w') as file:
    for line in lines:
        file.write(f'{line}\n')

8. Using With Blocks for Multiple Files

To work with multiple files simultaneously using with blocks:

with open('source.txt', 'r') as source, open('destination.txt', 'w') as destination:
    content = source.read()
    destination.write(content)

9. Deleting a File

To safely delete a file if it exists:

import os
if os.path.exists('example.txt'):
    os.remove('example.txt')
    print('File deleted.')
else:
    print('File does not exist.')

10. Reading and Writing Binary Files

To read from and write to a file in binary mode (useful for images, videos, etc.):

# Reading a binary file
with open('image.jpg', 'rb') as file:
    content = file.read()
# Writing to a binary file
with open('copy.jpg', 'wb') as file:
    file.write(content)

https://blog.stackademic.com/ultimate-python-cheat-sheet-practical-python-for-everyday-tasks-c267c1394ee8