If you're new to Python, understanding basic operations, data types, and conditional logic is essential. Let's recap some fundamental topics. We'll explore each topic with examples.
Chapter 1: Arithmetic Operators
Python provides a variety of operators that make it easy to perform mathematical operations. Here’s a quick rundown of the most common operators:
Syntax | Action | Example | Output |
---|---|---|---|
* |
Multiply | 4 * 10 |
40 |
+ |
Addition | 7 + 9 |
16 |
- |
Subtract | 23 - 4 |
19 |
/ |
Division | 27 / 3 |
9 |
** |
Power | 3 ** 2 |
9 |
% |
Modulo | 7 % 4 |
3 |
These operators help you work with numbers in your code. Here are some examples:
# Multiplication
result = 4 * 10
print(result) # Output: 40
# Addition
total = 7 + 9
print(total) # Output: 16
# Power
squared = 3 ** 2
print(squared) # Output: 9
You can also assign values to variables using these operators:
# Define total spend amount
total_spend = 3150.96
print(total_spend) # Output: 3150.96
Chapter 2: Data Types and Collections
In Python, you have various ways to store data, each suited to different types of tasks.
-
Strings: Used for text. You can define a string using either single or double quotes.
# Defining a string customer_name = 'George Boorman' print(customer_name) # Double quotes also work customer_name = "George Boorman"
-
Lists: A list is an ordered collection that can contain multiple values.
# Creating a list prices = [10, 20, 30, 15, 25, 35] # Accessing the first item print(prices[0]) # Output: 10
-
Dictionaries: A dictionary stores key-value pairs, allowing you to look up a value based on a key.
# Creating a dictionary products_dict = { "AG32": 10, "HT91": 20, "PL65": 30, "OS31": 15, "KB07": 25, "TR48": 35 } # Accessing a value by key print(products_dict["AG32"]) # Output: 10
-
Sets and Tuples:
- Set: A collection of unique elements.
- Tuple: An immutable list, meaning it cannot be changed after creation.
# Creating a set prices_set = {10, 20, 30, 15, 25, 35} # Creating a tuple prices_tuple = (10, 20, 30, 15, 25, 35)
Chapter 3: Conditional Keywords
Python includes several keywords to evaluate conditions, which are essential for decision-making in your code.
Keyword | Function |
---|---|
and |
Evaluate if multiple conditions are true |
or |
Evaluate if one or more conditions are true |
in |
Check if a value exists in a data structure |
not |
Evaluate if a value is not in a data structure |
Let's go over some examples to understand these keywords in action:
-
Using
and
:
age = 25
income = 50000
# Check if both conditions are true
if age > 20 and income > 30000:
print("Eligible for loan")
-
Using
or
:
day = "Sunday"
weather = "sunny"
# Check if either condition is true
if day == "Saturday" or weather == "sunny":
print("Let's go to the park!")
-
Using
in
:
fruits = ["apple", "banana", "cherry"]
# Check if a value is in the list
if "apple" in fruits:
print("Apple is available.")
-
Using
not
:
vegetables = ["carrot", "potato", "spinach"]
# Check if a value is not in the list
if "broccoli" not in vegetables:
print("Broccoli is not in the list.")
SUM UP
This overview covered the basics of arithmetic operations, various data types, and conditional keywords in Python. These are fundamental concepts that will help you build more complex programs.