Download It provides you all commands and more Cheat Sheet Artificial Intelligence in PDF only on Docsity!
# [ Python Basics ] [ cheatsheet ]
1. Basic Syntax and Operations
โ Print Statements: print("Hello, World!") โ Comments: # This is a single-line comment โ Multi-line Comments: '''This is a multi-line comment''' or """This is also a multi-line comment""" โ Variable Assignment: x = 10 โ Data Types: int , float , str , bool โ Type Checking: type(variable) โ Type Conversion: int("5") , str(20) โ Arithmetic Operations: + , - , ***** , / , // (integer division), % (modulus), ****** (exponentiation) โ Increment/Decrement: x += 1 , x -= 1 โ String Concatenation: 'Hello' + ' ' + 'World' โ String Multiplication: 'Python' * 3 โ Input from User: input("Enter your name: ")
2. Data Structures
โ List Creation: my_list = [1, 2, 3] โ Append to List: my_list.append(4) โ Insert into List: my_list.insert(1, 'a') โ Remove from List: my_list.remove('a') โ List Slicing: my_list[1:3] โ Sort List: sorted(my_list) , my_list.sort() โ Dictionary Creation: my_dict = {'key': 'value'} โ Access Dictionary Items: my_dict['key'] โ Add/Update Dictionary Item: my_dict['new_key'] = 'new_value' โ Remove Dictionary Item: del my_dict['key'] โ Tuple Creation: my_tuple = (1, 2, 3) โ Set Creation: my_set = {1, 2, 3} โ Add to Set: my_set.add(4) โ Remove from Set: my_set.remove(1)
3. Control Flow
โ If Statement: if condition:
โ If-Else Statement: if condition: else: โ If-Elif-Else Statement: if condition: elif condition: else: โ For Loop: for item in iterable: โ While Loop: while condition: โ Break: break โ Continue: continue โ Pass: pass โ List Comprehension: [expression for item in list] โ Dictionary Comprehension: {key: value for item in list}
4. Functions and Modules
โ Defining a Function: def my_function(): โ Function with Parameters: def my_function(param1, param2): โ Return Statement: return x โ Default Parameter Value: def my_function(param1, param2=5): โ Variable Length Arguments: def my_function(args):* , def my_function(kwargs): โ** Importing a Module: import math โ Importing Specific Functions: from math import sqrt โ Creating a Module: Save your functions in a .py file โ Using Pip: pip install package_name
5. Error Handling
โ Try-Except: try: except Exception: โ Multiple Except Blocks: try: except TypeError: except ValueError: โ Finally Block: try: except Exception: finally: โ Raise an Error: raise ValueError("A value error occurred")
6. File Handling
โ Open a File: file = open('file.txt', 'r') โ Read a File: file.read() โ Write to a File: file = open('file.txt', 'w'); file.write("Hello, World!") โ Append to a File: file = open('file.txt', 'a'); file.write("Hello, again!") โ Close a File: file.close() โ With Statement (Context Manager): with open('file.txt', 'r') as file:
10. Date and Time
โ Current Date and Time: from datetime import datetime; datetime.now() โ Specific Date: from datetime import date; date(2020, 1, 1) โ Formatting Date and Time: datetime.now().strftime('%Y-%m-%d %H:%M:%S') โ Parsing Date and Time Strings: datetime.strptime('2020-01-01', '%Y-%m-%d') โ Timedelta Objects: from datetime import timedelta; timedelta(days=1)
11. File Paths and Directories
โ List Files in Directory: import os; os.listdir('path/to/directory') โ Check if File Exists: os.path.exists('file.txt') โ Create a Directory: os.makedirs('new_directory') โ Change Current Working Directory: os.chdir('path/to/directory') โ Path Join: os.path.join('directory', 'file.txt')
12. Environment and System
โ System Commands: import os; os.system('command') โ Environment Variables: os.environ.get('VARIABLE_NAME') โ Current Working Directory: os.getcwd() โ Executing Shell Commands: import subprocess; subprocess.run(['ls', '-l'])
13. Networking
โ Simple HTTP Requests: import requests; response = requests.get('http://example.com') โ Parsing HTML: from bs4 import BeautifulSoup; soup = BeautifulSoup(response.text, 'html.parser') โ Socket Client: import socket; s = socket.socket(); s.connect(('hostname', port))
14. Debugging and Profiling
โ Print Debugging: print("Debug: ", variable) โ Using pdb: import pdb; pdb.set_trace() โ Profiling Python Code: import cProfile; cProfile.run('function()')
15. Testing
โ Writing Unit Tests: import unittest; class TestMyFunction(unittest.TestCase): โ Running a Test Case: if name == 'main': unittest.main() โ Assertions in Tests: self.assertEqual(function_to_test(input), expected_output)
16. Virtual Environments
โ Creating a Virtual Environment: python -m venv myenv โ Activating a Virtual Environment: source myenv/bin/activate (Linux/Mac), myenv\Scripts\activate (Windows) โ Deactivating a Virtual Environment: deactivate
17. Packaging and Distribution
โ Creating a Package: Organize your code in a directory with an init.py file. โ Setup Script: Writing a setup.py for package distribution. โ Installing Your Package: pip install. in your package directory. โ Uploading to PyPI: python setup.py sdist upload
18. Advanced String Formatting
โ Formatted String Literals (f-strings): name = "World"; f"Hello, {name}!" โ String Format Method: "{0}, {1}".format('Hello', 'World') โ Percent (%) Formatting: "%s, %s" % ('Hello', 'World')
19. Comprehensions Beyond Lists
โ Set Comprehensions: {x for x in 'hello world' if x not in 'aeiou'} โ Dictionary Comprehensions: {k: v for k, v in [('key1', 1), ('key2', 2)]}
20. Itertools and More Functional Tools
โ Itertools for Combining Data: import itertools; itertools.chain([1, 2], [3, 4]) โ Functional Programming Tools: map , filter , functools.reduce
21. Lambda Functions
โ Importing with Alias: import numpy as np; np.array([1, 2, 3]) โ Creating a Package: Create a directory with an init.py file and other module files.
27. Regular Expressions
โ Matching Strings: import re; re.match('p', 'python') โ Search Within Strings: re.search('n', 'python') โ Replacing Strings: re.sub('python', 'cython', 'I love python') โ Compiling Patterns: pattern = re.compile('python'); pattern.findall('I love python')
28. Data Serialization
โ JSON Serialization: import json; json.dumps({'name': 'John', 'age': 30}) โ JSON Deserialization: json.loads('{"name": "John", "age": 30}') โ Pickle Serialization: import pickle; pickle.dumps(obj) โ Pickle Deserialization: pickle.loads(pickled_data)
29. Multithreading and Multiprocessing
โ Creating Threads: from threading import Thread; t = Thread(target=function_name); t.start() โ Creating Processes: from multiprocessing import Process; p = Process(target=function_name); p.start() โ Joining Threads: t.join() โ Joining Processes: p.join()
30. Asynchronous Programming
โ Basic Coroutine: import asyncio; async def main(): await asyncio.sleep(1); print('done') โ Running Async Code: asyncio.run(main()) โ Async/Await with Functions: async def fetch_data(): data = await some_async_operation(); return data
