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Python Advanced

This page provides an introduction to python higher order functions, file, time and multithreading.

Lambda​

# defining lambda function
add = lambda x, y: x + y
max = lambda x, y: x if x > y else y
full_name = lambda first_name, last_name: first_name + " " + last_name

# calling lambda function
print(add(1, 2))
# o/p: 3

print(max(5, 6))
# o/p: 6

print(full_name("Spongbob", "Squarepants"))
# o/p: Spongbob Squarepants

Map​

def c_to_f(temp): return (temp * 9/5) + 32

celsius_temp = [0.0, 10.0, 20.0, 30.0, 40.0, 50.0]
fahrenheit_temp = list(map(c_to_f, celsius_temp))

print(fahrenheit_temp)
# o/p: 32.0, 50.0, 68.0, 86.0, 104.0, 122.0]

Filter​

def is_passing(grade): return grade >= 60

grades = [91, 32, 83, 44, 75, 56, 67]
passing_grades = list(filter(is_passing, grades))

print(passing_grades)
# o/p: [91, 83, 75, 67]

Reduce​

def add(x, y): return x + y

from functools import reduce 
prices = [11, 52, 67, 100]
total = reduce(add, prices)

print(total)
# o/p: 230

File Detection​

import os

file_path = "test.txt"

if os.path.exists(file_path):
  print(f"File exists")
  if os.path.isfile(file_path):
    print("That is a file")
  elif os.path.isdir(file_path):
    print("That is a directory")
else:
  print(f"File doesn't exists")

Write File​

txt_data = "I like pizza!"
file_path = "output.txt"

with open(file_path, "w") as file:
  file.write(txt_data)
  print(f"txt file {file_path} was created")
info

Different modes for file operations

  • "x" write the file if it doesn't exists.
  • "a" append
  • "w" overwrite.
  • "r" read

Read File​

file_path = "input.txt"

try:
  with open(file_path, "r") as file:
    content = file.read()
    print(content)
except FileNotFoundError:
  print("That file was not found")

Time​

import time 

start_time = time.perf_counter()
for i in range(10000):
  pass

end_time = time.perf_counter()
elapsed_time = end_time - start_time
print(f"Elapsed Time {elapsed_time:.6f}")

Date & Time​

import datetime

date = datetime.date(2025, 1, 2)
today = datetime.date.today()

print(date)
# o/p: 2025-01-02

print(today)
# o/p: 2024-10-28

time = datetime.time(12, 30, 0)
now = datetime.datetime.now()
now_formatted = now.strftime("%m-%d-%y %H:%M:%S")

print(time)
# o/p: 12:30:00

print(now)
# o/p: 2024-10-28 14:17:09.377378

print(now_formatted)
# o/p: 10-28-24 14:17:44

target_datetime = datetime.datetime(2030, 1, 2, 12, 30, 1)
current_datetime = datetime.datetime.now()

if target_datetime < current_datetime:
  print("Target date has passed")
else:
  print("Target date has not passed")
# o/p: Target date has not passed

Multithreading​

import threading
import time

def walk_dog(name):
  time.sleep(8)
  print(f"You finish walking the {name}")

def take_out_trash():
  time.sleep(4)
  print("You took out the trash")

def get_mail():
  time.sleep(2)
  print("You got the mail")

task_1 = threading.Thread(target=walk_dog, args=("Scooby", ))
task_1.start()

task_2 = threading.Thread(target=take_out_trash)
task_2.start()

task_3 = threading.Thread(target=get_mail)
task_3.start()

task_1.join()
task_2.join()
task_3.join()
print("All tasks are completed")
# o/p:
# You got the mail
# You took out the trash
# You finish walking the Scooby
# All tasks are completed

API Request​

import requests

base_url = "https://pokeapi.co/api/v2/"

def get_pokemon_info(name):
  url = f"{base_url}/pokemon/{name}"
  response = requests.get(url)
  
  if response.status_code == 200:
    pokemon_data = response.json()
    return pokemon_data
  else:
    print(f"Failed to retrieved data {response.status_code}")


pokemon_info = get_pokemon_info("pikachu")
if pokemon_info:
  print(f"Name: {pokemon_info['name'].capitalize()}")

Setup Python Project​

Click Here to see Python Project in github. Below are the steps to create python project template:

# create a directory
mkdir python-project-template && cd python-project-template

# create virtual environment for isolation
python3 -m venv venv

# Activate virtual environment
source venv/bin/activate

# create project structure
mkdir src tests

# make directory src & tests as a package by creating __init__.py
touch src/__init__.py
touch tests/__init__.py

# create source directory with hello world
echo "def hello_world():
    return 'Hello, World!'" > src/hello.py

# create test directory with sample test
echo "from src.hello import hello_world


def test_hello_world():
    assert hello_world() == 'Hello, World!'" > tests/test_hello_world.py

# create requirements.txt
pip3 freeze > requirements.txt

# create dev requirements
echo "pytest\npytest-cov\ntox\nblack\nisort\nflake8\npylint\nmypy" > requirements-dev.txt

# install dev requirements.txt and requirements-dev.txt
pip3 install -r requirements.txt -r requirements-dev.txt

# add .gitignore file
echo "venv/*\n.tox/*\n__pycache__/*" > .gitignore

We will be using tox for testing, create tox.ini in project root directory with below content:

# Tox configuration file to run tests and formatting checks.

[tox]
# List of environments to be tested. These are the Python versions to be used.
envlist = py38, py39, py310

[testenv]
setenv =
    PYTHONDONTWRITEBYTECODE=1
# This is the default environment.
# It runs commands for each Python version specified in the `envlist`.
commands =
    # Run tests using pytest
    pytest
    # Check if the code follows Black's code style without modifying it.
    black . --include "/(src|tests)/.*\.py"
    # Check if the code follows isort's import order without modifying it.
    isort src tests
    # Check for PEP8 violations and other code style issues using flake8.
    flake8 src tests
    # Run pylint for static code analysis, disabling certain checks.
    pylint --disable=C0114,C0116,C0115 --ignore=__init__.py src tests

[testenv:py38]
deps =
    -rrequirements-dev.txt

[testenv:py39]
deps =
    -rrequirements-dev.txt

[testenv:py310]
deps =
    -rrequirements-dev.txt

allowlist_externals =
    black

To install dependencies, run test cases, and apply formatting, run:

tox
# o/p:
# ...
#  py38: OK (4.57=setup[0.08]+cmd[0.64,0.38,0.39,1.69,1.39] seconds)
#  py39: OK (3.23=setup[0.03]+cmd[0.36,0.31,0.21,0.83,1.50] seconds)
#  py310: OK (3.40=setup[0.03]+cmd[0.39,0.47,0.27,0.82,1.41] seconds)
#  congratulations :) (11.27 seconds)

To run specific environment run:

tox -e py38
# o/p:
# ...
# py38: commands[1]> black . --include '/(src|tests)/.*\.py'
# All done! ✨ 🍰 ✨
# 4 files left unchanged.
# py38: commands[2]> isort src tests
# py38: commands[3]> flake8 src tests
# py38: commands[4]> pylint --disable=C0114,C0116,C0115 --ignore=__init__.py src tests
#   py38: OK (3.47=setup[0.06]+cmd[0.48,0.31,0.26,0.91,1.44] seconds)
#   congratulations :) (3.55 seconds)

Lastly create an empty repo and github and push the changes to github repo.