How To Convert Data Types in Python 3?

Type Conversion is also known as typecasting, is an important feature in Python that allows developers to convert a variable of one type into another. In Python 3, type conversion can be done both explicitly (manual conversion) and implicitly (automatic conversion by Python).

This article will explore how to Convert Data Types in Python 3 and explain Python’s built-in functions for converting data types.

Types of Data Type Conversion

1) Implicit Type Conversion

In Python, implicit conversion happens automatically during operations when the interpreter can safely transform one data type into another without losing information.

# Implicit Conversion
x = 5       # Integer
y = 2.0     # Float

# Adding integer and float results in float
result = x + y
print(result)          
print(type(result))    

7.0
<class 'float'>

• Here, Python converts the integer x into a float to perform the addition, ensuring that the result (7.0) is a float.

2) Explicit Type Conversion

Explicit conversion, or typecasting requires the developer to manually convert a variable from one data type to another using Python's built-in functions. This is especially useful when implicit conversion isn’t possible or when precision is necessary.

a = "42"
b = int(a)
print(type(b)) 

<class 'int'>

• In this case, the string "42" is explicitly converted to an integer using the int() function.

Common Built-In Functions for Type Conversion

Python offers a range of built-in functions for converting data types. Below are the most commonly used functions along with their examples:

Examples of Data Type Conversion

Here are examples of converting common data types:

String to Integer or Float

User inputs are typically strings, so we often need to convert them to numerical types for calculations. so converting it to an integer or float is common. Example: int("42") or float("3.14").

# String to Integer
x = "25"
a = int(x)
print(type(a))  

# String to Float
x = "25"
y = float(x)
print(type(y))

<class 'int'>
<class 'float'>

Integer or Float to String:

When combining numbers with text, we need to convert numbers to strings. Converting an integer to a string is often needed for tasks such as concatenating numbers with text.

# Integer to String
a = 42
b = str(a)
print(b)  

# Float to String
x = 3.14159
b = str(x)
print(b)  

42
3.14159

List to Tuple or Set:

Converting between collections is useful for different operations like removing duplicates (with sets) or ensuring immutability (with tuples).

# List to Tuple
a = [1, 2, 3]
b = tuple(a)
print(b)  

# List to Set
x = set(a)
print(x)  

(1, 2, 3)
{1, 2, 3}

Tuple or Set to List:

Converting it to a list can help when you need an ordered or indexable structure. It helps to preserves the original order of the elements since tuples are ordered.

a = (10, 20, 30, 40)
b = {3, 1, 4, 2, 2}

# Convert tuple and set to lists
x = list(a)
y = list(b)

# Print results
print(x)
print(y)

[10, 20, 30, 40]
[1, 2, 3, 4]

Dictionary from Key-Value Pairs:

Using the dict() function, you can create a dictionary from an iterable of key-value pairs. We can create dictionaries from a list of tuples or other iterable structures.

x = [("a", 1), ("b", 2), ("c", 3)]

y = dict(x)
print(y)  

{'a': 1, 'b': 2, 'c': 3}

Boolean Conversion

We can convert any value to a boolean. In Python, 0, None, and empty sequences are considered False, and all other values are True.

# Convert to Boolean
print(bool(0))  
print(bool(42))  
print(bool("")) 
print(bool("Hello"))  

False
True
False
True