Demonstration of List

  • Adding text to a list
  • This is a simulation where you can see the text getting added to the text box!

Dictionary Simulation

Welcome to the dictionary simulation! Below, you will find a list of words and their definitions. To view the definition of a word, simply click on the button next to it.

Word List

  • Apple

  • Banana

  • Cactus

  • Dolphin

  • Elephant

Dictionaries:

  • A dictionary is a collection of key-value pairs that are unordered, mutable, and indexed.
  • Dictionaries are defined using curly braces {} with key-value pairs separated by a colon (:).
  • Keys in a dictionary should be unique and immutable (strings, numbers, and tuples), while values can be of any data type.
  • Dictionaries can be accessed using the keys, using the squarebracket notation with the key name as the index.
  • You can also use the .get() method to retrieve a value for a given key. If the key does not exist, the method returns None (or a default value if provided).
  • Dictionaries have several built-in methods such as .keys(), .values(), and .items() to retrieve the keys, values, and key-value pairs respectively.
  • You can add, update, and remove elements from a dictionary using various built-in methods.

    2D Arrays:

  • A 2D array, also known as a matrix, is a collection of elements arranged in rows and columns.
  • A 2D array is defined using square brackets [] with each row separated by a comma, and each element within the row separated by a space.
  • You can access individual elements within a 2D array using square brackets and the row and column indices (e.g. arr[row][column]).
  • 2D arrays can be used to represent data that has two dimensions, such as an image or a spreadsheet.
  • You can perform various operations on 2D arrays such as transposing (swapping rows and columns), adding and subtracting, and multiplying by a scalar or another matrix.
  • There are several libraries available in Python, such as NumPy and Pandas, that provide more efficient and powerful tools for working with 2D arrays and matrices.

Example Matrix / 2d array

matrix = [
    [1, 2, 3],
    [4, 5, 6],
    [7, 8, 9]
]

Accessing Elements

To access an element in a 2D array, you need to specify the row and column indices. For example, to access the element in row 2, column 3 of the matrix array above (which contains the value 6), you would use the following syntax:

element = matrix[1][2]   # row 2, column 3

Modifying Elements

To modify an element in a 2D array, you can use the same syntax as for accessing elements. For example, to change the value of the element in row 2, column 3 of the matrix array above to 10, you would use the following syntax:

matrix[1][2] = 10   # row 2, column 3

Iterating and printing items

for row in matrix:
    for element in row:
        print(element)