Python String to int

By | September 28, 2021 In Python, integer numbers are represented as the whole numbers with no fraction value. In Python using the int and str data types we can store integer values however the arithmetic operators do not work on str datatype.  In this tutorial, we have provided the python code snippets which can convert Python str datatype to an int datatype.

Represent an Integer value in Python

An integer value can be stored as str and int data type, but it always suggested to save it as int.

Integer value as an str data type

>>> a = "200"

Integer value as an int data type

>>> a = 200

Convert str to int

In Python, we have a built-in function int() which can convert str datatype integer value to int datatype integer value. But while using the int() function we need to make sure that the string contains only integer or whole number, nothing else.

Example

s = "400"
i = int(s)
print(s)

Output

400

<Note>:The string value which we want to convert into an integer value must contain only whole or integer number else the int() function return an error.

Example

s = "200k"
i = int(s)

Traceback (most recent call last):
File "<stdin>", line 1, in <module>
ValueError: invalid literal for int() with base 10: '200k'

int() function parameters

The int() function can accepts two parameters:

• value.
• base.

Syntax

int(value , base)

Here the base signifies the base value of the passed value, and by default, the base value is 10(decimal).

There are 4 major number systems we can use to represent integer and whole numbers.

• Binary (base 2)
• octal (base 8)
• decimal (base 10)

Binary to int

When we want to convert a binary number to an integer value, then we need to pass its base value 2.

Example

>>>i = int(30.23)
>>> b = "1000"
>>> n = int(b, base=2)
>>> n
8

Octal to int

To convert an octal number to an integer, we need to mention the base 8. Octal numbers can only be represented using 0, 1, 2, 3, 4, 5, 6, and 7 numbers.

10 in octal means 8 in decimal or integer.

Example

>>> o = "10"
>>> i = int(o, base=8 )
>>> i
8

Decimal numbers

By default the int() function change all the valid values to decimal values.

Example

>>> d = "129"
>>> n = int(d, base= 10)
>>> n
129

To change a hexadecimal number to an integer, we need to pass the base value as 16. Hexadecimal can represent a number using 0 to 9 and A-F, which make its base count to 16.

Example

>>> hd = "1F"
>>> n = int(hd, base= 16)
>>> n
31

Python convert int to str

Similar to the int() function we have str() function in Python which can convert the passed value to string datatype.

Example

>>> f = 30.23
>>> s = str(f)
>>> s
'30.23'

>>> type(s)
<class 'str'>

<Note> The type() function returns the data type of the variable or object.

Summary

• The inbuilt int() function can convert the passed string value to its corresponding integer value.
• The string value we passed in the int() function must be an integer value or whole number, the function returns an error.
• The base parameter of int() function represents the number system base of the value.
• The str() function can convert any value to a string data value. 