Introduction to Python

Course Content

Introduction to Python

Introduction to Python

1. First Acquaintance with Python

The Very First Steps in Python How to Use Comments for Readability Perform Simple Math in Python Handle More Challenging Math in Python Bringing Python Fundamentals Together

2. Variables and Types in Python

How to Store Numbers in Python Python Naming Rules for Variables How to Work with Variables in Python Data Types in Python Challenge: Converting Kilometers to Miles Store Text with Strings in Python String Indexing in Python Negative Indexing and String Length in Python String Slicing in Python Challenge: Retrieving Letters from String String Concatenation in Python

3. Conditional Statements in Python

Boolean Data Type in Python Challenge: Working with Comparison Operators How to Combine Conditions in Python Challenge: Working with Logical Operators Membership Operators and Type Comparisons in Python How to Use if/else Expressions in Python Challenge: Running a Grocery Store Challenge: Creating Odd and Even Logic if/elif/else Expressions Challenge: Running Grocery Store Extended Challenge: Weather Adviser

4. Other Data Types in Python

Python Lists Common List Methods in Python Challenge: Updating List Nested Lists in Python Challenge: Retrieving Information from Nested List Python Tuples Common Tuple Methods in Python Challenge: Updating Tuple Nested Tuples in Python Challenge: Retrieving Information from Nested Tuple Python Dictionaries Challenge: Creating Dictionary Common Dictionary Methods in Python Challenge: Updating Dictionary

5. Loops in Python

Explore the while Loop in Python Challenge: Working with the While Loop Explore the for Loop in Python Challenge: Working with the For Loop Range Function in Python Challenge: Using the Range Function How to Iterate Over Indexes in Python Explore Nested Loops in Python

6. Functions in Python

Built-in Functions in Python Challenge: Converting Heights How to Create Functions in Pythons Challenge: Writing First Function Use of if/else Statements in Python Functions Challenge: Identifying Positive Values Functions Without Return in Python Challenge: Creating Logging Function Modifying Functions in Python Challenge: Updating Logic of the Function Lambda Functions in Python Challenge: Creating Lambda Function

Membership Operators and Type Comparisons in Python

Python also provides membership operators, which check whether a sequence exists within an object. In Python, sequence objects include strings, lists, tuples, and more. These will be explored in the next section.

The membership operators are in and not in. The in operator returns True if the sequence exists within the object. For example, let's check if the letter 'n' is in the word 'codefinity'.


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# Initial string
site = "codefinity"

# Using membership operator
print("n" in site)

A True result means the letter was found in the word. Conversely, the not in operator checks if a sequence is absent from an object.

Sometimes, it's necessary to verify an object's type. For example, when dividing an input by 2, the value must be numerical; otherwise, the operation will fail. There are two ways to check a value's type:

Using is: type(var) is int returns True only if var is an integer.
Using isinstance(): isinstance(var, int) does the same but works with multiple types.


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# Initial number
num = 3.5

# Checking if num is an integer
print(type(num) is int) # The first approach
print(isinstance(num, int)) # The second approach

As shown, both methods return False because 3.5 is a float, not an int.

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Section 3. Chapter 5

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