List of Python Articles

Environment information and settings

• Check Python Version on Command Line and in Scripts
• Get the OS Name and Version in Python
• Get and Change the Current Working Directory in Python
• Get the Path of the Current File (Script) in Python: __file__
• Get, Set, and Delete Environment Variables in Python: os.environ
• Get/Set the Recursion Limit in Python: sys.getrecursionlimit, sys.setrecursionlimit

Coding standards and conventions

• Python Indentation Rules
• Valid Variable Names and Naming Rules in Python
• Keywords and Reserved Words in Python
• Write a Long String on Multiple Lines in Python
• Method Chaining Across Multiple Lines in Python

pip (package-management system)

• How to Use pip (Install, Update, Uninstall Packages)
• How to Install Python Packages with pip and requirements.txt
• How to List Installed Python Packages with pip list/freeze
• Check the Versions of Python Packages

Imports

• How to Import Modules, Packages, Functions in Python
• Check and Add the Module Search Path in Python: sys.path
• What is if __name__ == '__main__' in Python

Handling exceptions, warnings, and assertions

• Try, except, else, finally in Python (Exception handling)
• The assert Statement in Python
• How to Ignore Warnings in Python
• The pass Statement in Python

Comments and docstrings

• How to Write a Comment and Comment Out Lines in Python
• Python Docstring Formats (Styles) and Examples

Command line arguments

• Command Line Arguments in Python: sys.argv, argparse
• Handle Boolean Arguments with argparse in Python

Standard inputs and outputs

• Take Input from User in Python: input()
• How to Use print() in Python
• Pretty-print in Python: pprint

Types and classes

• Get and Check the Type of an Object in Python: type(), isinstance()
• Convert Between bool (True/False) and Other Types in Python
• Check Subclass and Superclass in Python: issubclass, __bases__
• Duck Typing in Python: hasattr() and Abstract Base Class
• None in Python

Operators

• Arithmetic Operators in Python (+, -, , /, //, %, *)
• Boolean Operators in Python (and, or, not)
• Bitwise Operators in Python (AND, OR, XOR, NOT, SHIFT)
• Difference Between the == and is Operators in Python
• Chained Comparison (a < x < b) in Python
• Multiple Assignment in Python

Functions and arguments

• Define and Call Functions in Python (def, return)
• *args and **kwargs in Python (Variable-Length Arguments)
• Default Parameter Values in Python Functions
• Expand and Pass a List and Dictionary As Arguments in Python
• How to Return Multiple Values from a Function in Python
• Lambda Expressions in Python

for and while loops

• Python for Loop (With range, enumerate, zip)
• Use enumerate() and zip() Together in Python
• Break Out of Nested Loops in Python
• Python while Loop (Infinite Loop, break, continue)

if statements

• Python if Statement (if, elif, else)
• Conditional Expression (Ternary Operator) in Python

Lists (list)

Basics

• List vs. Array vs. numpy.ndarray in Python
• Initialize a List of Any Size with Specific Values in Python
• List Comprehensions in Python
• Apply a Function to Items of a List in Python: map()
• Filter (Extract/Remove) Items of a List with in Python: filter()
• Get the Size (Length, Number of Items) of a List in Python
• Compare Lists in Python
• The in Operator in Python (for List, String, Dictionary)
• Convert Between a List and a Tuple in Python

Adding and removing items

• Add an Item to a List in Python: append, extend, insert
• Remove an Item from a List in Python: remove, pop, clear, del

Extracting and replacing items

• Find the Index of an Item in a List in Python
• How to Slice a List, String, and Tuple in Python
• Extract, Replace, Convert Elements of a List in Python
• Extract and Replace Elements That Meet the Conditions of a List of Strings in Python
• Get the N-Largest/Smallest Elements from a List in Python
• Random Sample from a List in Python: random.choice, sample, choices
• How to Start enumerate() at 1 in Python
• Get Elements from Multiple Lists in Python: zip()

Sorting, reversing, and shuffling lists

• Sort a List, String, Tuple in Python: sort, sorted
• How to Use the key Argument in Python (sorted, max, etc.)
• Sort a List of Numeric Strings in Python
• Reverse a List, String, Tuple in Python: reverse, reversed
• Shuffle a List, String, Tuple in Python: random.shuffle, sample
• Swap Values ​​in a List or Values of Variables in Python
• Sort a 2D List in Python
• How to Transpose a List of Lists (2D List) in Python
• How to Flatten a List of Lists in Python
• Convert 1D Array to 2D Array in Python (numpy.ndarray, list)

Handling duplicate items

• Remove/Extract Duplicate Elements from List in Python
• Check If a List Has Duplicates in Python
• Extract Common/Non-common/Unique Elements from Multiple Lists in Python
• GROUP BY in Python: itertools.groupby

Other list operations

• Shallow and Deep Copy in Python: copy(), deepcopy()
• Convert a List of Strings and a List of Numbers to Each Other in Python
• Count Elements in a List in Python: collections.Counter
• Cartesian Product of Lists in Python: itertools.product

Tuples (tuple)

• Add, Update, Remove Tuple Items in Python
• A Tuple with One Element Requires a Comma in Python
• How to Unpack a Tuple or List in Python

Sets (set)

• Set Operations in Python (Union, Intersection, Symmetric Difference)

Dictionaries (dict)

• Create a Dictionary in Python: {}, dict(), Dict Comprehensions
• Add and Update an Item in a Dictionary in Python
• Merge Dictionaries in Python
• Remove an Item from a Dictionary in Python: pop, popitem, clear, del
• Add an Item If the Key Does Not Exist in dict in Python: setdefault
• Check If a Key/Value Exists in a Dictionary in Python
• Get a Value from a Dictionary by Key in Python
• Get Keys from a Dictionary by Value in Python
• Iterate Over Dictionary Keys, Values, and Items in Python
• Change a Key Name in a Dictionary in Python
• Swap Keys and Values in a Dictionary in Python
• Get Maximum/Minimum Values and Keys in Python Dictionaries
• Set Operations on Multiple Dictionary Keys in Python
• Extract Specific Key Values from a List of Dictionaries in Python
• Sort a List of Dictionaries by the Value of the Specific Key in Python

Strings (str)

Basics

• Create a String in Python: Single/Double/Triple Quotes, str()
• Get the Length of a String (number of Characters) in Python
• Concatenate Strings in Python: + Operator, join, etc.
• Replace Strings in Python: replace(), translate(), and Regex
• Split a String in Python (Delimiter, Line Breaks, Regex)
• Search for a String in Python (Check If a Substring Is Included/Get a Substring Position)
• String Comparison in Python (Exact/Partial Match, etc.)
• Extract a Substring from a String in Python (Position, Regex)
• Remove a Substring from a String in Python
• Count Characters or Substrings in a String in Python
• Handle Line Breaks (Newlines) in Strings in Python
• Uppercase and Lowercase Strings in Python (Conversion and Checking)
• Raw Strings in Python

Format

• Format Strings and Numbers in Python: format()
• How to Use f-strings in Python
• Pad Strings and Numbers with Zeros in Python (Zero-padding)
• Right-justify, Center, Left-justify Strings and Numbers in Python

Converting to numeric values

• Convert Binary, Octal, Decimal, and Hexadecimal in Python
• Convert a String to a Number (int, float) in Python
• Check If a String Is Numeric, Alphabetic, Alphanumeric, or Ascii

Regular expressions (Regex)

• Regular Expressions in Python: the re Module
• How to Use Regex Match Objects in Python

Other string operations

• Convert Between Unicode Code Point and Character: chr, ord
• Wrap and Truncate a String with textwrap in Python

Numerics (int adn float)

• Round Numbers in Python: round(), Decimal.quantize()
• Round Up/Down Decimals in Python: math.floor, math.ceil
• Get Absolute Values in Python: abs(), math.fabs()
• Generate Random Numbers (int and float) in Python
• Get Quotient and Remainder in Python: divmod()
• Check If a Number Is an Integer in Python
• Get the Fractional and Integer Parts in Python: math.modf()
• Integer (int) Has No Max Limit in Python 3
• Maximum and Minimum float Values in Python
• Check If the Floating Point Numbers Are Close in Python: math.isclose
• Infinity (inf) in Python
• What is nan in Python (float('nan'), math.nan, np.nan)
• Sign Function in Python: sign/signum/sgn, copysign
• Count the Number of 1 Bits in Python: int.bit_count

Mathematics

• Fractions (Rational Numbers) in Python
• Complex Numbers in Python
• Set Operations in Python (Union, Intersection, Symmetric Difference)
• Trigonometric Functions in Python: sin, cos, tan, arcsin, arccos, arctan
• Power and Logarithmic Functions in Python: exp, log, log10, log2
• Find GCD and LCM in Python: math.gcd(), lcm()
• Calculate Mean, Median, Mode, Variance, Standard Deviation in Python
• Cumulative Calculations in Python: itertools.accumulate()

Algorithms

• How to Use Deque in Python: collections.deque

Files and directories

Reading, writing, and creating files

• Read, Write, and Create Files in Python (with and open())

Creating directories

• Create a Directory in Python: mkdir(), makedirs()

Deleting, moving, coping files and directories

• Delete a File/Directory in Python: os.remove, shutil.rmtree
• Move a File/Directory in Python: shutil.move
• Copy a File/Directory in Python: shutil.copy, shutil.copytree

Checking existence, size, and timestamp

• Check If a File/Directory Exists in Python: os.path.exists, isfile, isdir
• Get the File/Directory Size in Python: os.path.getsize
• Get File Timestamp in Python: os.stat, os.path.getmtime

Path manipulations

• Get the Filename, Directory, Extension from a Path String in Python
• Get a List of File and Directory Names in Python
• How to Use glob() in Python
• How to Use pathlib in Python

CSV, JSON, and ZIP

• Read and Write CSV Files in Python
• Load, Parse, Serialize JSON Files and Strings in Python
• Zip and Unzip Files in Python: zipfile, shutil

Dates and times

• Handle Date and Time in Python: datetime
• Get the Current Date and Time in Python: datetime.now, date.today
• Measure Elapsed Time and Time Differences in Python
• Convert Between Isoformat String and datetime in Python
• Convert Unix Time (Epoch Time) to and from datetime in Python
• Create Calendar as text, HTML, List in Python
• Get the Number of Days and Weeks in a Month in Python
• Determine, Count, and List Leap Years in Python

Other built-in functions

• How to Use range() in Python
• How to Use len() in Python
• How to Use all() and any() in Python
• List Built-in Objects in Python: dir(__builtins__)

Other modules/libraries

• Infinite Iterators in Python: itertools.count, cycle, repeat
• The operator Module in Python: itemgetter, attrgetter, methodcaller
• Measure Execution Time with timeit in Python
• Guess MIME Type from Filename/URL with mimetypes in Python
• Copy and Paste Text to the Clipboard with pyperclip in Python
• Detect and Read Barcodes and QR Codes with ZBar in Python