Python Snippets

import os
import signal

os.kill(pid, signal.SIGTERM) #or signal.SIGKILL 

from urllib.parse import quote 

quote("value/with/slashes")

from typing import get_type_hints

Student(NamedTuple):
    name: Annotated[str, 'some marker']

get_type_hints(Student) == {'name': str}
get_type_hints(Student, include_extras=False) == {'name': str}
get_type_hints(Student, include_extras=True) == {
    'name': Annotated[str, 'some marker']
}
````

# [Type hints of a python module](https://stackoverflow.com/questions/53780735/what-is-the-type-hint-for-a-any-python-module)
```python
from types import ModuleType
import os

assert isinstance(os, ModuleType)

def _load_classes_from_directory(self, directory):
    classes = []
    for file_name in os.listdir(directory):
        if file_name.endswith(".py") and file_name != "__init__.py":
            module_name = os.path.splitext(file_name)[0]
            module_path = os.path.join(directory, file_name)

            # Import the module dynamically
            spec = spec_from_file_location(module_name, module_path)
            if spec is None or spec.loader is None:
                raise ValueError(
                    f"Error loading the spec of {module_name} from {module_path}"
                )
            module = module_from_spec(spec)
            spec.loader.exec_module(module)

            # Retrieve all classes from the module
            module_classes = inspect.getmembers(module, inspect.isclass)
            classes.extend(module_classes)

import sys

sys.path.append("**Put here the directory where you have the file with your function**")

from file import function

from functools import lru_cache
import time


@lru_cache()
def my_expensive_function(a, b, ttl_hash=None):
    del ttl_hash  # to emphasize we don't use it and to shut pylint up
    return a + b  # horrible CPU load...


def get_ttl_hash(seconds=3600):
    """Return the same value withing `seconds` time period"""
    return round(time.time() / seconds)


# somewhere in your code...
res = my_expensive_function(2, 2, ttl_hash=get_ttl_hash())
# cache will be updated once in an hour

  def x():
    y = True
    if y:
        a = 1
    print(a)  # "a" is possibly unbound

  def x():
    a = None
    y = True
    if y:
        a = 1
    print(a)  # "a" is possibly unbound

x = [1,2,3,4]
f = [1,11,22,33,44,3,4]

result = set(f) - set(x)

number = 1
print(f"{number:02d}")

file_ = Path('/to/some/file')
file_.stat().st_mtime

assert datetime.now().timestamp - file_.stat().st_mtime < 60

import logging
logging.basicConfig(format='%(asctime)s %(message)s')
logging.warning('is when this event was logged.')

>>> from urllib.parse import unquote
>>> print(unquote("%CE%B1%CE%BB%20"))
αλ

file_ = Path('/to/some/file')
file_.read_text()

import os

os.path.getmtime(path)

sorted(glob.glob('*.png'))

import os
sorted(glob.glob('*.png'), key=os.path.getmtime)

import os
sorted(glob.glob('*.png'), key=os.path.getsize)

pkgdir = sys.modules['<mypkg>'].__path__[0]
fullpath = os.path.join(pkgdir, <myfile>)
shutil.copy(fullpath, os.getcwd())

>>> from pathlib import Path
>>> p = Path('/home/lyz/')
>>> h = Path('/home/')
>>> p.relative_to(h)
PosixPath('lyz')

import os
import shutil

os.rename("path/to/current/file.foo", "path/to/new/destination/for/file.foo")
os.replace("path/to/current/file.foo", "path/to/new/destination/for/file.foo")
shutil.move("path/to/current/file.foo", "path/to/new/destination/for/file.foo")

import logging

try:
    1 / 0
except BaseException:
    logging.exception("An exception was thrown!")

ERROR:root:An exception was thrown!
Traceback (most recent call last):
File ".../Desktop/test.py", line 4, in <module>
    1/0
ZeroDivisionError: division by zero

logging.critical("An exception was thrown!", exc_info=True)
logging.error("An exception was thrown!", exc_info=True)
logging.warning("An exception was thrown!", exc_info=True)
logging.info("An exception was thrown!", exc_info=True)
logging.debug("An exception was thrown!", exc_info=True)

# or the general form
logging.log(level, "An exception was thrown!", exc_info=True)

import traceback

try:
    1 / 0
except Exception:
    traceback.print_exc()

Traceback (most recent call last):
  File "C:\scripts\divide_by_zero.py", line 4, in <module>
    1/0
ZeroDivisionError: division by zero

>>> a = ['a', 'b']
>>> b = ['c', 'd', 'b']
>>> set(a) & set(b)
{'b'}

for x in b:
  if x in a:
    a.remove(x)

from pathlib import Path

for path in Path("src").rglob("*.c"):
    print(path.name)

import fnmatch
import os

matches = []
for root, dirnames, filenames in os.walk("src"):
    for filename in fnmatch.filter(filenames, "*.c"):
        matches.append(os.path.join(root, filename))

>>> name = 'John'
>>> name.ljust(15)
'John           '

import os

os.uname()[1]

import platform

platform.node()

import socket

socket.gethostname()

pathlib.Path("/tmp/sub1/sub2").mkdir(parents=True, exist_ok=True)

pathlib.Path("/tmp/file.txt").touch(exist_ok=True)

global_conf_path = xdg_home / "autoimport" / "config.toml"
global_conf_path.parent.mkdir(parents=True)
global_conf_path.touch(exist_ok=True)

>>> length = 1
>>> print(f'length = {length:03}')
length = 001

now = datetime.now()
today.strftime("We are the %d, %b %Y")

pip install pyfiglet

from pyfiglet import figlet_format

print(figlet_format("09 : 30"))

from pyfiglet import Figlet

f = Figlet(font="standard", width=100)
print(f.renderText("aaaaaaaaaaaaaaaaa"))

datetime.datetime.now().strftime("%Y-%m-%dT%H:%M:%S")

class ServiceStatus(BaseModel):
    """Model the docker status of a service."""

    name: str
    environment: Environment

class Environment(str, Enum):
    """Set the possible environments."""

    STAGING = "staging"
    PRODUCTION = "production"

    @classmethod
    def get_by_value(cls, value: str) -> Enum:
        """Return the Enum element that meets a value"""
        return [member for member in cls if member.value == value][0]

ServiceStatus(name="test", environment=Environment.get_by_value("production"))

list([0 for y in list(range(10))])  # [consider-using-generator]
tuple([0 for y in list(range(10))])  # [consider-using-generator]
sum([y**2 for y in list(range(10))])  # [consider-using-generator]
max([y**2 for y in list(range(10))])  # [consider-using-generator]
min([y**2 for y in list(range(10))])  # [consider-using-generator]

list(0 for y in list(range(10)))
tuple(0 for y in list(range(10)))
sum(y**2 for y in list(range(10)))
max(y**2 for y in list(range(10)))
min(y**2 for y in list(range(10)))

import subprocess


def example():
    proc = subprocess.run("ls")
    return proc.stdout

byte_var.decode("utf-8")

ps = subprocess.Popen(("ps", "-A"), stdout=subprocess.PIPE)
output = subprocess.check_output(("grep", "process_name"), stdin=ps.stdout)
ps.wait()

import subprocess

p = subprocess.run(["myapp"], input="data_to_write", text=True)

subprocess.run(
    ["xclip", "-selection", "clipboard", "-i"],
    input="text to be copied",
    text=True,
    check=True,
)

subprocess.check_output(["xclip", "-o", "-selection", "clipboard"]).decode("utf-8")

import random

a = random.randint(1, 10)

def port_in_use(port):
    """Test if a local port is used."""
    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    with suppress(OSError):
        sock.bind(("0.0.0.0", port))
        return True
    sock.close()
    return False

from dataclasses import dataclass
from inspect import signature


@dataclass
class Container:
    user_id: int
    body: str

    @classmethod
    def from_kwargs(cls, **kwargs):
        # fetch the constructor's signature
        cls_fields = {field for field in signature(cls).parameters}

        # split the kwargs into native ones and new ones
        native_args, new_args = {}, {}
        for key, value in kwargs.items():
            if key in cls_fields:
                native_args[key] = value
            else:
                new_args[key] = value

        # use the native ones to create the class ...
        ret = cls(**native_args)

        # ... and add the new ones by hand
        for new_key, new_value in new_args.items():
            setattr(ret, new_key, new_value)
        return ret

params = {"user_id": 1, "body": "foo", "bar": "baz", "amount": 10}
Container(**params)  # still doesn't work, raises a TypeError
c = Container.from_kwargs(**params)
print(c.bar)  # prints: 'baz'

txt = "I like bananas"

x = txt.replace("bananas", "apples")

>>> from email.utils import parsedate_to_datetime
>>> datestr = 'Sun, 09 Mar 1997 13:45:00 -0500'
>>> parsedate_to_datetime(datestr)
datetime.datetime(1997, 3, 9, 13, 45, tzinfo=datetime.timezone(datetime.timedelta(-1, 68400)))

>>> import datetime
>>> from email import utils
>>> nowdt = datetime.datetime.now()
>>> utils.format_datetime(nowdt)
'Tue, 10 Feb 2020 10:06:53 -0000'

import urllib.parse
from pydantic import AnyHttpUrl


def _normalize_url(url: str) -> AnyHttpUrl:
    """Encode url to make it compatible with AnyHttpUrl."""
    return typing.cast(
        AnyHttpUrl,
        urllib.parse.quote(url, ":/"),
    )

# Bad
idx = 0
for el in iterable:
    ...
    idx += 1

# Good
for idx, el in enumerate(iterable):
    ...

class G:
    @classmethod
    @property
    def __doc__(cls):
        return f"A doc for {cls.__name__!r}"

# N801: class name 'classproperty' should use CapWords convention, but it's a decorator.
# C0103: Class name "classproperty" doesn't conform to PascalCase naming style but it's
# a decorator.
class classproperty:  # noqa: N801, C0103
    """Define a class property.

    From Python 3.9 you can directly use the decorators directly.

    class G:
        @classmethod
        @property
        def __doc__(cls):
            return f'A doc for {cls.__name__!r}'
    """

    def __init__(self, function: Callable[..., Any]) -> None:
        """Initialize the decorator."""
        self.function = function

    # ANN401: Any not allowed in typings, but I don't know how to narrow the hints in
    # this case.
    def __get__(self, owner_self: Any, owner_cls: Any) -> Any:  # noqa: ANN401
        """Return the desired value."""
        return self.function(owner_self)

subprocess.terminate()

a.update(b)

numbers = [1, 2, 3, 2, 5, 3, 3, 5, 6, 3, 4, 5, 7]

duplicates = [number for number in numbers if numbers.count(number) > 1]
unique_duplicates = list(set(duplicates))

# Returns: [2, 3, 5]

from collections import Counter

numbers = [1, 2, 3, 2, 5, 3, 3, 5, 6, 3, 4, 5, 7]

counts = dict(Counter(numbers))
duplicates = {key: value for key, value in counts.items() if value > 1}

# Returns: {2: 2, 3: 4, 5: 3}

unique = list(set(numbers))

# Returns: [1, 2, 3, 4, 5, 6, 7]

import gzip
import shutil

with gzip.open("file.txt.gz", "rb") as f_in:
    with open("file.txt", "wb") as f_out:
        shutil.copyfileobj(f_in, f_out)

def compress(tar_file, members):
    """
    Adds files (`members`) to a tar_file and compress it
    """
    tar = tarfile.open(tar_file, mode="w:gz")

    for member in members:
        tar.add(member)

    tar.close()


def decompress(tar_file, path, members=None):
    """
    Extracts `tar_file` and puts the `members` to `path`.
    If members is None, all members on `tar_file` will be extracted.
    """
    tar = tarfile.open(tar_file, mode="r:gz")
    if members is None:
        members = tar.getmembers()
    for member in members:
        tar.extract(member, path=path)
    tar.close()

bs = BeautifulSoup(requests.get(url), "lxml")

import traceback

# `e` is an exception object that you get from somewhere
traceback_str = "".join(traceback.format_tb(e.__traceback__))

sh_logger = logging.getLogger("sh")
sh_logger.setLevel(logging.WARN)

[x[0] for x in os.walk(directory)]

import os

os.rename("path/to/current/file.foo", "path/to/new/destination/for/file.foo")

regex = re.compile(
    r"(?<![-\.\d])(?:0{0,2}?[0-9]\.|1\d?\d?\.|2[0-5]?[0-5]?\.){3}"
    r'(?:0{0,2}?[0-9]|1\d?\d?|2[0-5]?[0-5]?)(?![\.\d])"^[0-9]{1,3}*$'
)

>>> set([1,2,6,8]) - set([2,3,5,8])
set([1, 6])

import shutil

shutil.copytree("bar", "foo")

import shutil

shutil.copyfile(src_file, dest_file)

import io
from contextlib import redirect_stdout

f = io.StringIO()
with redirect_stdout(f):
    do_something(my_object)
out = f.getvalue()

import tempfile

dirpath = tempfile.mkdtemp()

@pytest.fixture(name="change_test_dir")
def change_test_dir_(request: SubRequest) -> Any:
    os.chdir(request.fspath.dirname)
    yield
    os.chdir(request.config.invocation_dir)

url = "abcdc.com"
url.removesuffix(".com")  # Returns 'abcdc'
url.removeprefix("abcdc.")  # Returns 'com'

url = "abcdc.com"
if url.endswith(".com"):
    url = url[:-4]

import re

url = "abcdc.com"
url = re.sub("\.com$", "", url)

t = [[1, 2, 3], [4, 5, 6], [7], [8, 9]]
flat_list = [item for sublist in t for item in sublist]

mystring = "_" * len(mystring)

a = ["a", "b"]

index = a.index("b")

>>> l=[[1,2,3],[4,5,6],[7,8,9]]
>>> [list(i) for i in zip(*l)]
... [[1, 4, 7], [2, 5, 8], [3, 6, 9]]

def _is_list_of_lists(data: Any) -> bool:
    """Check if data is a list of strings."""
    if data and isinstance(data, list):
        return all(isinstance(elem, list) for elem in data)
    else:
        return False

>>> small.items() <= big.items()
True

class Shape:
    pass


class Rectangle(Shape):
    def __init__(self, length, width):
        self.length = length
        self.width = width
        self.area = length * width

    def get_area(self):
        return self.length * self.width


class Square(Rectangle):
    def __init__(self, length):
        Rectangle.__init__(self, length, length)

>>> isinstance(a, Rectangle)
True

>>> type(a) == Rectangle
False

setup(
    name="pynbox",
    packages=find_packages("src"),
    package_dir={"": "src"},
    package_data={"pynbox": ["py.typed", "assets/config.yaml"]},

import pkg_resources

file_path = (pkg_resources.resource_filename("pynbox", "assets/config.yaml"),)

import os

os.remove("demofile.txt")

import time

start = time.time()
print("hello")
end = time.time()
print(end - start)

>>> list(itertools.combinations('ABC', 2))
[('A', 'B'), ('A', 'C'), ('B', 'C')]

pip install html2text

import html2text

html = open("foobar.html").read()
print(html2text.html2text(html))

>>> import datetime
>>> datetime.datetime.fromtimestamp(1347517370).strftime('%c')
  '2012-09-13 02:22:50'

from dateutil import parser

parser.parse("Aug 28 1999 12:00AM")  # datetime.datetime(1999, 8, 28, 0, 0)

datetime.datetime.strptime("2013-W26", "%Y-W%W-%w")

pip install git+git://github.com/path/to/repository@master

install_requires = [
    "some-pkg @ git+ssh://git@github.com/someorgname/pkg-repo-name@v1.1#egg=some-pkg",
]

HTTPError: 400 Bad Request from https://test.pypi.org/legacy/
Invalid value for requires_dist. Error: Can't have direct dependency: 'deepdiff @ git+git://github.com/lyz-code/deepdiff@master'

from setuptools.command.install import install
from subprocess import getoutput

# ignore: cannot subclass install, has type Any. And what would you do?
class PostInstall(install):  # type: ignore
    """Install direct dependency.

    Pypi doesn't allow uploading packages with direct dependencies, so we need to
    install them manually.
    """

    def run(self) -> None:
        """Install dependencies."""
        install.run(self)
        print(getoutput("pip install git+git://github.com/lyz-code/deepdiff@master"))


setup(cmdclass={"install": PostInstall})

def test_dir(directory):
    from os.path import exists
    from os import makedirs

    if not exists(directory):
        makedirs(directory)


def test_file(filepath, mode):
    """Check if a file exist and is accessible."""

    def check_mode(os_mode, mode):
        if os.path.isfile(filepath) and os.access(filepath, os_mode):
            return
        else:
            raise IOError("Can't access the file with mode " + mode)

    if mode is "r":
        check_mode(os.R_OK, mode)
    elif mode is "w":
        check_mode(os.W_OK, mode)
    elif mode is "a":
        check_mode(os.R_OK, mode)
        check_mode(os.W_OK, mode)

os.path.splitext("/path/to/some/file.txt")[0]

import os

directory = "/path/to/directory"
for entry in os.scandir(directory):
    if (entry.path.endswith(".jpg") or entry.path.endswith(".png")) and entry.is_file():
        print(entry.path)

if not os.path.exists(directory):
    os.makedirs(directory)

from pathlib import Path

Path("path/to/file.txt").touch()

current = datetime.datetime(mydate.year, mydate.month, 1)
next_month = datetime.datetime(
    mydate.year + int(mydate.month / 12), ((mydate.month % 12) + 1), 1
)

>>> import datetime
>>> datetime.datetime(2010, 6, 16).isocalendar()[1]
24

import datetime

d = "2013-W26"
r = datetime.datetime.strptime(d + "-1", "%Y-W%W-%w")

import calendar

>> calendar.month_name[3]
'March'

def int_to_ordinal(number: int) -> str:
    """Convert an integer into its ordinal representation.

    make_ordinal(0)   => '0th'
    make_ordinal(3)   => '3rd'
    make_ordinal(122) => '122nd'
    make_ordinal(213) => '213th'

    Args:
        number: Number to convert

    Returns:
        ordinal representation of the number
    """
    suffix = ["th", "st", "nd", "rd", "th"][min(number % 10, 4)]
    if 11 <= (number % 100) <= 13:
        suffix = "th"
    return f"{number}{suffix}"

>>> sorted([5, 2, 3, 1, 4])
[1, 2, 3, 4, 5]

>>> sorted("This is a test string from Andrew".split(), key=str.lower)
['a', 'Andrew', 'from', 'is', 'string', 'test', 'This']

>>> from operator import itemgetter
>>> student_tuples = [
    ('john', 'A', 15),
    ('jane', 'B', 12),
    ('dave', 'B', 10),
]

>>> sorted(student_tuples, key=itemgetter(2))   # sort by age
[('dave', 'B', 10), ('jane', 'B', 12), ('john', 'A', 15)]

>>> from operator import attrgetter
>>> class Student:
    def __init__(self, name, grade, age):
        self.name = name
        self.grade = grade
        self.age = age

    def __repr__(self):
        return repr((self.name, self.grade, self.age))

>>> student_objects = [
    Student('john', 'A', 15),
    Student('jane', 'B', 12),
    Student('dave', 'B', 10),
]

>>> sorted(student_objects, key=attrgetter('age'))   # sort by age
[('dave', 'B', 10), ('jane', 'B', 12), ('john', 'A', 15)]

>>> sorted(student_tuples, key=itemgetter(1,2))
[('john', 'A', 15), ('dave', 'B', 10), ('jane', 'B', 12)]

>>> sorted(student_objects, key=attrgetter('grade', 'age'))
[('john', 'A', 15), ('dave', 'B', 10), ('jane', 'B', 12)]

>>> data = [('red', 1), ('blue', 1), ('red', 2), ('blue', 2)]

>>> sorted(data, key=itemgetter(0))
[('blue', 1), ('blue', 2), ('red', 1), ('red', 2)]

>>> s = sorted(student_objects, key=attrgetter('age'))     # sort on secondary key

>>> sorted(s, key=attrgetter('grade'), reverse=True)       # now sort on primary key, descending
[('dave', 'B', 10), ('jane', 'B', 12), ('john', 'A', 15)]

>>> def multisort(xs, specs):
    for key, reverse in reversed(specs):
        xs.sort(key=attrgetter(key), reverse=reverse)
    return xs

>>> multisort(list(student_objects), (('grade', True), ('age', False)))
[('dave', 'B', 10), ('jane', 'B', 12), ('john', 'A', 15)]

ut.sort(key=lambda x: x.count, reverse=True)

newlist = sorted(ut, key=lambda x: x.body.id_, reverse=True)

@dataclass(frozen=True)
class Search:
    center: str
    distance: str


se = Search("a", "b")
for key, value in se.__dict__.items():
    print(key, value)

pip install cryptography

from os import chmod
from cryptography.hazmat.primitives import serialization
from cryptography.hazmat.primitives.asymmetric import rsa
from cryptography.hazmat.backends import default_backend as crypto_default_backend

private_key = rsa.generate_private_key(
    backend=crypto_default_backend(), public_exponent=65537, key_size=4096
)
pem = private_key.private_bytes(
    encoding=serialization.Encoding.PEM,
    format=serialization.PrivateFormat.TraditionalOpenSSL,
    encryption_algorithm=serialization.NoEncryption(),
)

with open("/tmp/private.key", "wb") as content_file:
    chmod("/tmp/private.key", 0600)
    content_file.write(pem)

public_key = (
    private_key.public_key().public_bytes(
        encoding=serialization.Encoding.OpenSSH,
        format=serialization.PublicFormat.OpenSSH,
    )
    + b" user@email.org"
)
with open("/tmp/public.key", "wb") as content_file:
    content_file.write(public_key)

def test():
    # end first line with \ to avoid the empty line!
    s = """\
hello
  world
"""

import textwrap


def test():
    # end first line with \ to avoid the empty line!
    s = """\
    hello
      world
    """
    print(repr(s))  # prints '    hello\n      world\n    '
    print(repr(textwrap.dedent(s)))  # prints 'hello\n  world\n'

pip install playsound

from playsound import playsound

playsound("path/to/file.wav")

import copy

d = {...}
d2 = copy.deepcopy(d)

pip install pyprojroot

from pyprojroot import here

here()

if hasattr(a, "property"):
    a.property

for i in [1, 2, 3]:
    print(i)
    if i == 3:
        break
else:
    print("for loop was not broken")

z = x + y

z = {**x, **y}

class Error(Exception):
    """Base class for exceptions in this module."""


class ConceptNotFoundError(Error):
    """Transactions with unmatched concept."""

    def __init__(self, message: str, transactions: List[Transaction]) -> None:
        """Initialize the exception."""
        self.message = message
        self.transactions = transactions
        super().__init__(self.message)

import importlib

module = importlib.import_module("os")
module_class = module.getcwd

relative_module = importlib.import_module(".model", package="mypackage")
class_to_extract = "MyModel"
extracted_class = geattr(relative_module, class_to_extract)

from dateutil import tz

myTimeZone = tz.tzlocal()

from datetime import datetime
from dateutil import tz

localisedDatetime = datetime.now(tz=tz.tzlocal())

>> sentence = "add funny Emojis"
>> sentence[0].upper() + sentence[1:]
Add funny Emojis

import datetime

today = datetime.date.today()
last_monday = today - datetime.timedelta(days=today.weekday())