Python Tutorial

• Python Add PYTHONPATH
• Python Code Blocks and Indentation
• Python Comment
• Python Variable
• Python Data Type
• Python Type Conversion and Casting
• Python Input and Output
• Python Operator
• Python Iterator
• Python Generator

Python Flow Control

• Python if else
• Python for Loops
• Python while Loops
• Python break Statement
• Python continue Statement
• Python pass Statement
• Python switch Statement

Python Functions

• Python Function
• Python Recursion
• Python Anonymous/Lambda Function
• Python Modules
• Python Package

Python Data Types

• Python Number
• Python String
• Python List
• Python Tuple
• Python Set
• Python Dictionary

Python Date and Time

• Python datetime
• strftime(): from datetime to readable string
• strptime(): read string to datetime
• Get current date and time
• Make a time delay
• Convert between local time and UTC time
• Get whole program execution time
• Iterate through a range of dates
• Get the last day of month
• Add/subtract a day
• Convert seconds to HH:MM:SS

Python Files

• Python Open and Close File
• Python Read File
• Python Write File
• Python Move File
• Python Remove File and Directory
• Read Write CSV file
• Read Write JSON file
• Zip File and Directory
• List all files of a directory
• List all sub-directories of directory
• Check a file or directory exists
• Create a directory safely
• Get current directory and file path
• Read big file
• Web page and file download over HTTP
• Search and replace a line to file
• Get file modification time
• Read specific lines from a file by line number
• Check file size
• Get filename and extension

Python String

• String updating, replacing and deleting
• Formatting of Strings
• String format converting
• Convert ASCII string
• String Escape Sequencing
• String lower and upper case
• Find substring in a string
• Count all occurrences of a substring
• Compare two strings
• Split a string into a list
• Split strings into words with multiple delimiters
• Extract numbers from a string
• Conbine items in a list to a single string
• Put a int variable inseide a string
• Compare string in case insensitive
• Check if multiple strings exist in another string
• Check if string exists in a list of strings
• Generate random string
• Remove trailing whitespace in strings

Python List

• List items Adding
• List items Accessing
• List items removing
• List items modifying
• List items iterating
• List items sorting
• List Comprehension
• Convert string representation of list to a list
• Clone a list
• Rotate a list
• Remove duplicates from list
• Define a two-dimensional array
• Sort a list of lists by value
• Sort list based on values from another list
• Sort a list of objects by an attribute of the objects
• Split a list into evenly sized chunks
• Creare a flat list out of a nested list
• Get all possible combinations of a list's elements
• Get the Cartesian product of a series of lists
• Find the index of an element in a list
• Concatenate two list
• Count the occurrences of a list item
• Transpose list of lists
• Find the difference between two lists
• Select items from list randomly
• Iterate a list as (current, next) pair
• Shuffle a list
• Find the cumulative sum of numbers in a list
• Get unique values from a list
• Generate all permutations of a list
• Find the intersection between two lists
• Find the duplicates in a list
• Check item in list
• Convert a list to a string
• Find the average of a list
• Alternate combine two lists
• Extract specific element from each sublist

Python Dictionary

• Add and Modify Dictionary elements
• Delete elements from Dictionary
• Sort dictionary by key
• Sort dictionary by value
• Combine and merge dictionaries
• Convert a String representation of a Dictionary to a dictionary
• Get key by value in dictionary
• Copy a dictionary and edit the copy only
• Create dictionary with dict comprehension and iterables
• Get key with maximum value in dictionary
• Make dictionary from list
• Filter dictionary to contain specific keys

Python Variable

• Python Global Variables and Global Keyword
• Python Local and Nonlocal Variables
• Python Static Class variables
• Create variable variables
• Create variables dynamically in while loop
• Test Single Variable in Multiple Values
• Swap two variables
• Set a Python variable to 'undefined'
• Set and access environment variables

Python Input/Output

• Formatting Output
• Interactive Input/Output
• Indefinitely Request User Input Until a Valid Response
• Read user input as number
• Pretty print JSON
• Print number

Python Exceptions

• Python Exception and Error
• Python AssertionError
• Python AttributeError
• Python EOFError
• Python FloatingPointError
• Python GeneratorExit
• Python ImportError and ModuleNotFoundError
• Python IndexError
• Python KeyError
• Python MemoryError
• Python NameError
• Python OverflowError
• Python TypeError

Python Advanced

• Access the index in for loops
• Change index of a for loop
• ** operator in a function call
• * operator in a function call
• Sort a list of tuples by value
• Transpose list of tuples
• Calculate Euclidean distance btween two points
• Resize an image and keep its aspect ratio
• Check number
• Generate random integers

How to concatenate two list in Python

In Python, you can concatenate two lists using the + operator. This will create a new list containing elements from both lists in the order they appear.

Here's an example:

list1 = [1, 2, 3]
list2 = [4, 5, 6]

# Concatenate the lists
concatenated_list = list1 + list2
print(concatenated_list)

Output:

[1, 2, 3, 4, 5, 6]

Alternatively, you can use the extend() method of a list to append the elements of another list to the end of it. This method modifies the original list in-place.

list1 = [1, 2, 3]
list2 = [4, 5, 6]

# Append the elements of list2 to list1
list1.extend(list2)
print(list1)

Output:

[1, 2, 3, 4, 5, 6]

Keep in mind that using the extend() method will modify the original list, while using the + operator will create a new list without changing the original lists.

1. Python concatenate two lists:

   list1 = [1, 2, 3]
   list2 = [4, 5, 6]
   result = list1 + list2
   print(result)  # [1, 2, 3, 4, 5, 6]
   

2. Extend one list with another in Python:

   list1 = [1, 2, 3]
   list2 = [4, 5, 6]
   list1.extend(list2)
   print(list1)  # [1, 2, 3, 4, 5, 6]
   

3. List concatenation vs. append in Python:

   list1 = [1, 2, 3]
   list2 = [4, 5, 6]
   
   # Using concatenation
   concatenated_list = list1 + list2
   print(concatenated_list)  # [1, 2, 3, 4, 5, 6]
   
   # Using append
   for item in list2:
       list1.append(item)
   print(list1)  # [1, 2, 3, 4, 5, 6]
   

4. Python zip() function for concatenating lists:

   list1 = [1, 2, 3]
   list2 = ['a', 'b', 'c']
   result = list(zip(list1, list2))
   print(result)  # [(1, 'a'), (2, 'b'), (3, 'c')]
   

5. List concatenation with itertools.chain in Python:

   from itertools import chain
   
   list1 = [1, 2, 3]
   list2 = [4, 5, 6]
   result = list(chain(list1, list2))
   print(result)  # [1, 2, 3, 4, 5, 6]
   

6. Concatenating lists with list comprehension in Python:

   list1 = [1, 2, 3]
   list2 = [4, 5, 6]
   result = [item for sublist in [list1, list2] for item in sublist]
   print(result)  # [1, 2, 3, 4, 5, 6]
   

7. Merging lists using the * operator in Python:

   list1 = [1, 2, 3]
   list2 = [4, 5, 6]
   result = [*list1, *list2]
   print(result)  # [1, 2, 3, 4, 5, 6]
   

8. List concatenation with the += operator in Python:

   list1 = [1, 2, 3]
   list2 = [4, 5, 6]
   list1 += list2
   print(list1)  # [1, 2, 3, 4, 5, 6]
   

9. Concatenate lists and remove duplicates in Python:

   list1 = [1, 2, 3]
   list2 = [3, 4, 5]
   result = list(set(list1 + list2))
   print(result)  # [1, 2, 3, 4, 5]
   

10. Append elements from one list to another in Python:

    list1 = [1, 2, 3]
    list2 = [4, 5, 6]
    list1.extend(list2)
    print(list1)  # [1, 2, 3, 4, 5, 6]