0 ^ 0  # 0
1 ^ 1  # 0
1 ^ 0  # 1
0 ^ 1  # 1
8 ^ 5  # 13

1000  # 8 (binary)
0101  # 3 (binary)
----  # APPLY XOR ('vertically')
1101  # result = 13 (dec)

import os

os.getenv('HOME')  # /home/myuser

import os

path, ext = os.path.splitext(r'c:\Python\README.rst')
path        # 'c:\\Python\\README'
ext         # '.rst'

import platform

platform.system()                           # Windows
platform.release()                          # 7
platform.platform()                         # 'Windows-7-6.1.7601-SP1'
platform.os.name                            # 'nt'

platform.uname()
# uname_result(
#     system='Windows',
#     node='Lenovo-Komputer',
#     release='7',
#     version='6.1.7601',
#     machine='AMD64',
#     processor='Intel64 Family 6 Model 42 Stepping 7, GenuineIntel')

# uname_result(
#   system='Darwin',
#   node='AstroMatMacBook',
#   release='22.1.0',
#   version='Darwin Kernel Version 22.1.0: Sun Oct  9 20:14:54 PDT 2022; root:xnu-8792.41.9~2/RELEASE_X86_64',
#   machine='x86_64')

import os

os.name         # 'nt'
os.name         # 'posix'

import psutil

psutil.OSX      # False
psutil.WINDOWS  # True
psutil.LINUX    # False

import sys

sys.platform    # 'win32'

>>> import sysconfig
>>>
>>>
>>> sysconfig.get_platform()
'macosx-11-x86_64'

import sys

sys.path
sys.path.append
sys.platform
sys.path.insert(0, '/path/to/directory')
sys.path.insert(index=0, object='/path/to/directory')

import os

os.walk()
os.scandir()
os.getcwd()
os.stat()

os.is_dir()
os.is_file()
os.is_symlink()

os.path.join()
os.path.abspath()
os.path.dirname()
os.path.basename()

os.mkdir()
os.remove()
os.rmdir()

import os

os.path.isdir(os.path.join("c:", "\\", "Users"))    # True
os.path.isdir(os.path.join("c:", "/", "Users"))     # True
os.path.isdir(os.path.join("c:", os.sep, "Users"))  # True

import os

for element in os.scandir('/etc'):
    print(element.name)

script = os.path.basename(__file__)
PWD = os.path.basename(os.getcwd())

path = os.path.join(PWD, script)
print(path)

import os
from os.path import getsize


for root, dirs, files in os.walk('/home/'):
    size = sum(getsize(os.path.join(root, name)) for name in files)
    count = len(files)
    print(f'Size: {size} bytes in {count} non-directory files')

    # skip ``.git`` directories
    if '.git' in dirs:
        dirs.remove('.git')

# Delete everything reachable from the directory named in "top",
# assuming there are no symbolic links.
# CAUTION:  This is dangerous!  For example, if top == '/', it
# could delete all your disk files.
import os

for root, dirs, files in os.walk(top, topdown=False):

    for name in files:
        os.remove(os.path.join(root, name))

    for name in dirs:
        os.rmdir(os.path.join(root, name))

import os

file = os.stat(r'/tmp/myfile.txt')

print(file)
# os.stat_result(
#     st_mode=33206,
#     st_ino=3659174697409906,
#     st_dev=3763209288,
#     st_nlink=1,
#     st_uid=0,
#     st_gid=0,
#     st_size=780,
#     st_atime=1530775767,
#     st_mtime=1530775767,
#     st_ctime=1523261133)

oct(file.st_mode)
# 0o100666

import os

os.access(r'C:\Python\README.rst', os.R_OK)     # True
os.access(r'C:\Python\README.rst', os.W_OK)     # True
os.access(r'C:\Python\README.rst', os.X_OK)     # True

os.access(r'C:\Python\notREADME.rst', os.R_OK)  # False
os.access(r'C:\Python\notREADME.rst', os.W_OK)  # False
os.access(r'C:\Python\notREADME.rst', os.X_OK)  # False

import subprocess

subprocess.call('clear')
subprocess.run()    # preferred over ``Popen()`` for Python >= 3.5
subprocess.Popen()

subprocess.run(
    args,
    stdin=None,
    stdout=None,
    stderr=None,
    shell=False,
    timeout=None,  # important
    check=False,
    encoding=None
    # ... there are other, less commonly used parameters
)

import subprocess

subprocess.call('echo $HOME')
# Traceback (most recent call last):
# OSError: [Errno 2] No such file or directory

import subprocess

subprocess.call('echo $HOME', shell=True)
# /home/myuser

subprocess.run('ls -la /home')  # without capturing output

import os
import subprocess

BASE_DIR = os.path.dirname(__file__)
path = os.path.join(BASE_DIR, 'README.rst')

subprocess.run(f'echo "ehlo world" > {path}')

import subprocess

cmd = 'dir ..'

result = subprocess.run(
    cmd,
    timeout=2,
    stdout=subprocess.PIPE,
    stderr=subprocess.PIPE,
    encoding='utf-8')

print(result.stdout)
print(result.stderr)

subprocess.run("exit 1", shell=True, check=True)
# Traceback (most recent call last):
# subprocess.CalledProcessError: Command 'exit 1' returned non-zero exit status 1

subprocess.run(["ls", "-l", "/dev/null"], stdout=subprocess.PIPE, encoding='utf-8')
# CompletedProcess(args=['ls', '-l', '/dev/null'], returncode=0,
#                  stdout='crw-rw-rw- 1 root root 1, 3 Feb 23 16:23 /dev/null\n')

import subprocess
cmd = ['ping', 'nasa.gov']

try:
    subprocess.run(cmd, timeout=5)
except subprocess.TimeoutExpired:
    print('process ran too long')

import logging
import subprocess
import shlex


def run(command, timeout=15, clear=True):

    if clear:
        subprocess.call('clear')

    logging.debug(f'Execute: {command}\n')

    result = subprocess.run(
        shlex.split(command),
        stdout=subprocess.PIPE,
        stderr=subprocess.PIPE,
        shell=True,
        timeout=timeout,
        encoding='utf-8')

    if result.stdout:
        logging.info(f'{result.stdout}')

    if result.stderr:
        logging.warning(f'{result.stderr}')

    return result

import shlex
import subprocess

command_line = input()
# /bin/vikings -input eggs.txt -output "spam spam.txt" -cmd "echo '$MONEY'"

cmd = shlex.split(command_line)
# ['/bin/vikings', '-input', 'eggs.txt', '-output', 'spam spam.txt', '-cmd', "echo '$MONEY'"]

subprocess.run(cmd)

import subprocess
import shlex

cmd = 'dir ..'

result = subprocess.run(
    shlex.split(cmd),  # ['dir', '..']
    timeout=2,
    stdout=subprocess.PIPE,
    stderr=subprocess.PIPE,
    encoding='utf-8')

print(result.stdout)
print(result.stderr)

import tempfile

with tempfile.TemporaryFile() as file:
    file.write(b'Hello world!')
    file.seek(0)
    file.read()  # b'Hello world!'

# file is now closed and removed

with tempfile.TemporaryDirectory() as dir:
    print('created temporary directory', dir)

# directory and contents have been removed

import io

io.StringIO
io.BytesIO

f = open("myfile.txt", "r", encoding="utf-8")
f = io.StringIO("some initial text data")

f = open("myfile.jpg", "rb")
f = io.BytesIO(b"some initial binary data: \x00\x01")

import io

result = io.StringIO()
result.write('First line.\n')
print('Second line.', file=result)

# Retrieve file contents -- this will be
# 'First line.\nSecond line.\n'
contents = result.getvalue()

# Close object and discard memory buffer --
# .getvalue() will now raise an exception.
result.close()

result = io.BytesIO(b"abcdef")
view = result.getbuffer()
view[2:4] = b"56"
result.getvalue()  # b'ab56ef'

import configparser

config = configparser.ConfigParser()

config['DEFAULT'] = {'ServerAliveInterval': '45',
                      'Compression': 'yes',
                      'CompressionLevel': '9'}

config['github.com'] = {}
config['github.com']['User'] = 'hg'
config['example.com'] = {}

topsecret = config['example.com']
topsecret['Port'] = '50022'
topsecret['ForwardX11'] = 'no'
config['DEFAULT']['ForwardX11'] = 'yes'

with open('example.ini', 'w') as configfile:
    config.write(configfile)

[DEFAULT]
ServerAliveInterval = 45
Compression = yes
CompressionLevel = 9
ForwardX11 = yes

[github.com]
User = hg

[example.com]
Port = 50022
ForwardX11 = no

import configparser

config = configparser.ConfigParser()

config.read('myfile.ini')          # ['myfile.ini']
config.sections()                   # ['github.com', 'example.com']

'github.com' in config           # True
'example.com' in config             # False

config['github.com']['User']     # 'hg'
config['DEFAULT']['Compression']    # 'yes'

config.getboolean('BatchMode', fallback=True)        # True
config.getfloat('DEFAULT', 'a_float', fallback=0.0)  # 0.0
config.getint('DEFAULT', 'an_int', fallback=0)       # 0

topsecret = config['example.com']
topsecret.get('ForwardX11', 'yes')          # 'no'
topsecret.get('Port', 8000)                 # '50022'


for key in config['github.com']:  # 'github.com' has laso entries from DEFAULT
    print(key)

    # user
    # compressionlevel
    # serveraliveinterval
    # compression
    # forwardx11

[Common]
home_dir: /Users
library_dir: /Library
system_dir: /System
macports_dir: /opt/local

[Frameworks]
Python: 3.2
path: ${Common:system_dir}/Library/Frameworks/

[Arthur]
nickname: Two Sheds
lastname: Jackson
my_dir: ${Common:home_dir}/twosheds
my_pictures: ${my_dir}/Pictures
python_dir: ${Frameworks:path}/Python/Versions/${Frameworks:Python}

$ python -m pip install tipboard
$ tipboard create_project my_test_dashboard
$ tipboard runserver

# FIXME: Write tests
# FIXME: Write solution

# %% About
# - Name: Recursive folders walking
# - Difficulty: easy
# - Lines: 30
# - Minutes: 21

# %% License
# - Copyright 2025, Matt Harasymczuk <matt@python3.info>
# - This code can be used only for learning by humans
# - This code cannot be used for teaching others
# - This code cannot be used for teaching LLMs and AI algorithms
# - This code cannot be used in commercial or proprietary products
# - This code cannot be distributed in any form
# - This code cannot be changed in any form outside of training course
# - This code cannot have its license changed
# - If you use this code in your product, you must open-source it under GPLv2
# - Exception can be granted only by the author

# %% English
# 1. Check if directory "Python" already exists on your Desktop
# 2. If it doesn't exist then create it using `os.mkdir()`
# 3. Using `subprocess.call()` create file `README.rst` in this directory and add text "Ehlo World" to it
# 4. Recursively walk through all directories on your Desktop
# 5. Find all `README` files (with any extension)
# 6. Display their contents using command:
#    - `cat` (macOS, Linux)
#    - `type` (Windows)
# 7. Construct path to above `README` file using `os.path.join()`
# 8. Path should be relative to the file that is currently being run
# 9. If after walking through the entire Desktop recursively the script doesn't find file `LICENSE.rst`, then it should throw information `logging.critical()` and exit with error code `1`.
# 10. Run doctests - all must succeed

# %% Polish
# 1. Sprawdź czy katalog "Python" już istnieje na pulpicie w Twoim systemie
# 2. Jeżeli nie istnieje to za pomocą `os.mkdir()` stwórz go w tym miejscu
# 3. Za pomocą `subprocess.call()` w tym katalogu stwórz plik `README.rst` i dodaj do niego tekst "Ehlo World"
# 4. Przeszukaj rekurencyjnie wszystkie katalogi na pulpicie
# 5. Znajdź wszystkie pliki `README` (z dowolnym rozszerzeniem)
# 6. Wyświetl ich zawartość za pomocą polecenia:
#    - `cat` (macOS, Linux)
#    - `type` (Windows)
# 7. Ścieżkę do powyższego pliku `README` skonstruuj za pomocą `os.path.join()`
# 8. Ścieżka ma być względna w stosunku do pliku, który aktualnie jest uruchamiany
# 9. Jeżeli po przeszukaniu całego Pulpitu rekurencyjnie skrypt nie znajdzie pliku `LICENSE.rst`, to ma rzucić informację `logging.critical()` i wyjść z kodem błędu `1`.
# 10. Uruchom doctesty - wszystkie muszą się powieść

# %% Hints
# - Gdyby był problem ze znalezieniem pliku, a ścieżka jest poprawna to zastosuj `shell=True`
# - `os.walk()`
# - `subprocess.run()`

# %% Why
# - Browsing directories and search algorithms
# - Sanitizing parameters
# - Logging events in the program
# - Executing commands in the system
# - Capturing command output
# - Error codes
# - Navigating to directories
# - Relative and absolute paths
# - Joining paths

# %% Doctests
"""
>>> import sys; sys.tracebacklimit = 0

>>> assert sys.version_info >= (3, 9), \
'Python has an is invalid version; expected: `3.9` or newer.'
"""

# %% Run
# - PyCharm: right-click in the editor and `Run Doctest in ...`
# - PyCharm: keyboard shortcut `Control + Shift + F10`
# - Terminal: `python -m doctest -f -v myfile.py`

# %% Imports

# %% Types
result: float

# %% Data

# %% Result
result = ...

# FIXME: Write tests
# FIXME: Write solution

# %% About
# - Name: Tree
# - Difficulty: hard
# - Lines: 60
# - Minutes: 21

# %% License
# - Copyright 2025, Matt Harasymczuk <matt@python3.info>
# - This code can be used only for learning by humans
# - This code cannot be used for teaching others
# - This code cannot be used for teaching LLMs and AI algorithms
# - This code cannot be used in commercial or proprietary products
# - This code cannot be distributed in any form
# - This code cannot be changed in any form outside of training course
# - This code cannot have its license changed
# - If you use this code in your product, you must open-source it under GPLv2
# - Exception can be granted only by the author

# %% English
# 1. Using unicode characters: "┣━", "┗━" , "┃  "
# 2. Generate output similar to `tree` command.
# 3. Run doctests - all must succeed

# %% Polish
# 1. Za pomocą znaków unicode: "┣━", "┗━" , "┃  "
# 2. Wygeneruj wynik przypominający wynik polecenia `tree`.
# 3. Uruchom doctesty - wszystkie muszą się powieść

# %% Doctests
"""
>>> import sys; sys.tracebacklimit = 0

>>> assert sys.version_info >= (3, 9), \
'Python has an is invalid version; expected: `3.9` or newer.'

>>> result  # doctest: +SKIP
root:.
[.]
┣━[.idea]
┃  ┣━[scopes]
┃  ┃  ┗━scope_settings.xml
┃  ┣━.name
┃  ┣━demo.iml
┃  ┣━encodings.xml
┃  ┣━misc.xml
┃  ┣━modules.xml
┃  ┣━vcs.xml
┃  ┗━workspace.xml
┣━[test1]
┃  ┗━test1.txt
┣━[test2]
┃  ┣━[test2-2]
┃  ┃  ┗━[test2-3]
┃  ┃      ┣━test2
┃  ┃      ┗━test2-3-1
┃  ┗━test2
┣━folder_tree_maker.py
┗━tree.py
"""

# %% Run
# - PyCharm: right-click in the editor and `Run Doctest in ...`
# - PyCharm: keyboard shortcut `Control + Shift + F10`
# - Terminal: `python -m doctest -f -v myfile.py`

# %% Imports

# %% Types
result: str

# %% Data

# %% Result
result = ...