Untitled Quiz

Python Installation

• Download Anaconda from www.anaconda.com/downloads
• Free "No Install" options are available:
  • jupyter.org/try
  • Google Colab Online Notebooks
• Using free "No Install" options may present challenges in uploading user code, data, or notebooks
• File saving may not be possible in free versions

Jupyter Notebook

• Keyboard shortcuts are available through the Help menu
• Toggle header and toolbar can be accessed through the View menu

Add Number to Cells

• Use the menu, view, then toggle line number.
• Use the keyboard shortcut or press ESC then L.

Basic Data Types

• Integers: Whole numbers (e.g., 3, 300, 200) - int type
• Floating-point: Numbers with a decimal point (e.g., 2.3, 4.6, 100.0) - float type
• Strings: Ordered sequence of characters (e.g., "hello", 'Sammy', "2000"), or even emojis - str type
• Lists: Ordered sequence of objects (e.g., [10,"hello",200.3]) - list type
• Dictionaries: Unordered key-value pairs (e.g., {"mykey":"value","name": "Frankie"}) - dict type
• Tuples: Ordered immutable sequence of objects (e.g., (10,"hello",200.3)) - tup type
• Sets: Unordered collection of unique objects (e.g., {"a","b"}) - set type
• Booleans: Logical values indicating True or False - bool type

Example Data Types

• a=10, type is int
• b=10.5, type is float
• c="adel", type is str
• d=[10,20.5,"adel"], type is list
• e={"K1":"vaue1", "k2": "Value2"}, type is dict
• f=(10,20.5,"adel"), type is tuple
• s={"a","b",10,20.5}, type is set

Order of Precedence in Python

• Parentheses, Exponential (exp), Multiplication, Division, Addition, Subtraction
• Multiple variable assignments in one line (e.g., a, b, c = 10, 20, 30)

Basic Data Types: Tuples and Lists

• Tuples: Ordered, immutable sequences. Once an element is in a tuple, it cannot be changed or reassigned. Uses parentheses (e.g., (1,2,3)).
• Lists: Ordered, mutable sequences. Elements can be changed. Uses square brackets (e.g., [1,2,3]).

Basic Data Types: Numbers

• Integers: Whole numbers (e.g., 3, 100)
• Floating-point: Numbers with decimal points (e.g., 3.14, 10.0)

Floating Point Arithmetic Issues

• Python's floating-point representation has limitations leading to inaccuracies in calculations involving decimal values (e.g., 0.1 + 0.2 ≠ 0.3).

Variable Assignments

• Variable names cannot start with numbers or contain spaces. Use underscores to separate words in variable names (e.g., my_dogs).
• Variables should typically be lowercase.
• Avoid Python keywords like list and str as variable names.
• Python uses dynamic typing, meaning you can reassign a variable to a different data type.

Variable Assignments: Example Usage

• myincome = 1000
• tax = 0.2
• mytax = myincome * tax

Print Multiple Variables

• print("The band for", name, "is", band, "out of", 10)

Strings: Basic Concepts

• Strings are sequences of characters. Enclose strings in either single ('...') or double ("...") quotes.
• Indexing: Access individual characters (e.g., s[0] for the first character)
• Slicing: Extract subsets of characters (e.g., s[1:4] to get characters from index 1 to 3)

Strings: Example Indices

• Characters: h -> e -> l -> l -> o
• Indices: 0 -> 1 -> 2 -> 3 -> 4
• Reverse Indices: -5 -> -4 -> -3 -> -2 -> -1

Strings: Escape Sequences

• '\n' (newline character) - starts a new line in a string print operation
• '\t' (tab character) - provides indentation in print operations

String Formatting

• String interpolation, using print("Hello" + my_name), helps display data in strings.

String Indexing and Slicing: Summary

• Indexing grabs a single character.
• Slicing extracts a subsection of a string (e.g., slice[start:end:step]).

String Operations: Mutability

• Strings are immutable. Attempts to assign a new value to a single index in a string will result in an error.

String Operations: Concatenation

• The "+" operator can be used to concatenate strings (e.g., 'Hello' + ' ' + 'World!')

String Operations: Functions

• Use x.split('character') to split a string based on a specific character

String Operations: Immutability

• Strings are immutable (cannot be changed after creation).

String Formatting for Printing

• Use format() method and f-strings:
  • {variable} in format strings
  • f'{variable}' in f-strings

List Methods

• append(): Adds an element to the end of a list.
• insert(): Inserts an element at a specific index.
• pop(): Removes and returns the item at a specific index (or the last item if no index is given).
• remove(): Removes the first occurrence of a specific item.
• sort(): Sorts a list in place. sorted(mylist) sorts a list and returns a new sorted list, without modifying the original.
• extend(): Add multiple items to the end of a list.
• reverse(): Reverses a list.

Dictionaries: Basic Concepts

• Dictionaries are unordered collections of key-value pairs.
• Use curly braces {} to define dictionaries, with keys and values separated by colons.

Dictionary Operations

• Access values by their keys: my_dict['key1']
• Adding new key-value pair: d['K4'] = 400
• Modifying an existing value: d['K3'] = 5000
• Iterating over keys/values: for k, v in my_dict.items():
• keys(), values(), items() methods return views.

Tuples: Summary

• Tuples are similar to lists but are immutable. Values inside tuples cannot be changed. Use parenthesis (()).

Sets: Basic Concepts

• Sets are unordered collections of unique elements.
• Use curly braces {} to create sets or use the set() constructor to create a set from a list.

Set Methods

• add(): Adds an item to the set. If the item already exists, it's ignored.
• remove(): Removes the specific item, resulting in an error if the item doesn't exist.
• pop(): Removes and returns an arbitrary item from the set.
• discard(): Removes the specific item if it exists. Otherwise, it does nothing. No error if the item doesn't exist.

Boolean: Summary

• Booleans represent truth values (True or False).

Math Operations

• import math
• math.pow(10, 2) calculates 10 raised to the power of 2 (10 squared)

Files

• I/O (Input/Output): Reading and writing to files in python.
• Modes:
  • read only ('r') - open only to read from the file
  • write only ('w') - overwrite the file or create a new one
  • append ('a') - add to the file, without overwriting existing content
  • reading and writing ('r+') - open to modify existing file
  • writing and reading ('w+') - overwrite the file but read from file
• Using .read() to read the entire file content
• Using .readline() to read a single line from a file.
• Using .readlines() read all lines (from file) into a list
• Using .seek(0) to reset the cursor to the beginning of the file.
• with statement:
  • A useful way for opening and closing files, ensuring the file is always closed, and avoiding potential errors.

Assessment Test: Examples

• Strings: Find the square root of 100, reverse and print the string 'hello'.
• Lists: Build a list of three zeroes in two different ways, reassign a nested list element.
• Dictionaries: Access nested dictionary values.
• Tuples: Explain the difference between tuples and lists.
• Sets: Remove duplicates, Explain about set method and what they can do.
• Booleans: Explain boolean operators.