Data, such as variables, is not always of the same type. For example, if you concatenate two variables of type text, the result is that the texts are joined together.

On the other hand, if the variables are numbers, the result is the sum of the numbers.

And if you try to perform an operation with two types that are not compatible, you will get an error.

This is Python's way of displaying error messages, which you should get used to. You can see from the message what the error was and on which line it occurred. 

). The error in this case is incompatible operands (left and right side) for the plus operator.

There are quite a few different data types and you can also define more yourself. Here are the built-in data types in Python and roughly their purpose. You don't need to remember these yet, but take a look.

Folder (keys with a value, like a dictionary): 

Set (a list where values are not repeated): 

Python can infer the data type itself. You can test this with the 

The most common data types for numbers are 

 (Floating point) means a decimal number.

Let's go back to the previous example. The code caused an error because the operands of the plus operator (left and right side) were not compatible, one was 

We could solve the problem by forcing the number to text, or text to number. Let's try both.

The number is converted to text with the 

The text is converted to a number using the 

This is an example of how the program should function.

Change the variables (forcing the type) into numbers. You can create new variables or save the current numbers in the format (e.g. 

). You can also directly convert the value returned by the input function into a number (

first_number = int(input("First number: "))

Make a program that asks the user for two numbers and then prints their sum.

Task 1

Data types

## What are data types?

Data, such as variables, is not always of the same type. For example, if you concatenate two variables of type text, the result is that the texts are joined together.

```python
a = "3"
b = "5"
print(a + b)
35
```

On the other hand, if the variables are numbers, the result is the sum of the numbers.

```python
a = 3
b = 5
print(a + b)
8
```

And if you try to perform an operation with two types that are not compatible, you will get an error.

```python
a = 3
b = "5"
print(a + b)

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: unsupported operand type(s) for +: 'int' and 'str'
```

This is Python's way of displaying error messages, which you should get used to. You can see from the message what the error was and on which line it occurred. **int** means number (*Integer*) and **str** is the data type for text (*String*). The error in this case is incompatible operands (left and right side) for the plus operator.

---

## What types of data are there?

There are quite a few different data types and you can also define more yourself. Here are the built-in data types in Python and roughly their purpose. You don't need to remember these yet, but take a look.

- Text: **str**
- Numbers: **int**, **float**, **complex**
- Lists: **list**, **tuple**, **range**
- Folder (keys with a value, like a dictionary): **dict**
- Set (a list where values are not repeated): **set**, **frozenset**
- Boolean value (true or false): **bool**
- Binary data types: **bytes**, **bytearray**, **memoryview**
- Empty value: **None**

---

## How is the data type defined?

Python can infer the data type itself. You can test this with the **type** function.

```python
x = 3

print(type(x))
<class 'int'>
```

```python
y = "3"

print(type(y))
<class 'str'>
```

---

## Numbers

The most common data types for numbers are **int** and **float**. **int** (Integer) means an integer, while **float** (Floating point) means a decimal number.

```python
a = 3
print(type(a))
<class 'int'>
```

```python
b = 3.5
print(type(b))
<class 'float'>
```

---

## Text

The data type of the text is **str**, which stands for *String* (*string*).

```python
a = "hi"
print(type(a))
<class 'str'>
```

---

## Truth value

The data type for True/False values is **bool**, which stands for *Boolean*.

```python
a = True
print(type(a))
<class 'bool'>
```

```python
b = False
print(type(b))
<class 'bool'>
```

---

## Type coercion

Let's go back to the previous example. The code caused an error because the operands of the plus operator (left and right side) were not compatible, one was **int** and the other was **str**, which cannot be concatenated together.

```python
a = 3
b = "5"
print(a + b)

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: unsupported operand type(s) for +: 'int' and 'str'
```

We could solve the problem by forcing the number to text, or text to number. Let's try both.

The number is converted to text with the **str** function.

```python
a = 3
b = "5"
print(str(a) + b)

35
```

The text is converted to a number using the **int** function.

```python
a = 3
b = "5"
print(a + int(b))

8
```

---

## Exercise

This is an example of how the program should function.

```sh
Enter the first number: 5
Enter another number: 10
15
```

@exercise 8400c7b041f3


Let's learn the basics of programming with Python. Aimed at complete beginners.

Welcome to the Python programming course! This course is intended for anyone who wants to learn to program in the Python language but has no previous programming experience. Python is a very popular programming language used in various applications, such as web development, data processing, artificial intelligence, and data analytics.

The aim of the course is to provide you with basic knowledge of Python programming and help you develop your skills step by step. We will go through basic concepts such as variables, conditional statements, and loops, and you will learn how to use Python for data processing.

The course consists of various learning materials, such as videos, written materials, and exercises, that allow you to apply what you have learned in practice. As the course progresses, you will learn more complex programming concepts and techniques and achieve a solid foundation in Python programming.

It is highly recommended to take this course immediately after the basic course, as understanding vulnerabilities is much easier if you understand code. Besides, coding is fun!

Are you ready to start your journey in the world of Python programming? Join this exciting course and start learning today!

Data types

What are data types?

Learn to hack — start here