What is %d and %s in python?

In this article, we will see the difference between %s and %d in Python. Here, we start with the proper explanation of one at a time, then both, and at last compare these.

What does %s do in Python?

The % symbol is used in Python with a large variety of data types and configurations. It is used as an argument specifier and string formatter. %s specifically is used to perform the concatenation of strings together. It allows us to format a value inside a string. It is used to incorporate another string within a string. It automatically provides type conversion from value to string.

How to Use %s in Python

The %s operator is put where the string is to be specified. The number of values you want to append to a string should be equivalent to the number specified in parentheses after the % operator at the end of the string value. The following code illustrates the usage of the %s symbol :

Python3

name = "Geek"

print("Hey, %s!" % name)

Output

Hey, Geek!

What does %d do in Python? 

The %d operator is used as a placeholder to specify integer values, decimals, or numbers. It allows us to print numbers within strings or other values. The %d operator is put where the integer is to be specified. Floating-point numbers are converted automatically to decimal values. 

Python3

num = 2021

print("%d is here!!" % num)

Output

2021 is here!!

How to Use %d in Python

The decimal and rational numbers are rounded off to the absolute integral part and the numbers after the decimal are scraped off, that is only the integers are extracted. The following code illustrates the usage of %d with decimal and fractional numbers:

Python3

frac_num = 8/3

print("Rational number formatting using %d")

print("%d is equal to 8/3 using this operator." % frac_num)

dec_num = 10.9785

print("Decimal number formatting using %d")

print("%d is equal to 10.9785 using this operator." % dec_num)

Output

Rational number formatting using %d
2 is equal to 8/3 using this operator.
Decimal number formatting using %d
10 is equal to 10.9785 using this operator.

Difference Between %s and %d?

We can use a combination of operators also within a single program. Before that first, clear some concepts by comparing as given below :

%s operator

%d operator

It is used as a placeholder for string values.  It is used as a placeholder for numeric values.
Uses string conversion via str() before formatting. Uses decimal conversion via int() before formatting.
%s can accept numeric values also and it automatically does the type conversion.   In case a string is specified for the %d operator a type error is returned.

Common Errors Using %s and %d

Example 1:

The %s automatically converts a numeric value to a string without throwing an error. 

Python3

name = "Sita"

age = 22

print("Using %s ")

print ("%s's age is %s."%(name,age))

Output

Using %s 
Sita's age is 22.

Example 2:

 The %d, however, can only be used for numeric values. Otherwise, an error is returned. 

Python3

name = "Sita"

age = 22

print("Using %d")

print ("%d's age is %d."%(name,age))

Error

Using %d
Traceback (most recent call last):
 File "<string>", line 4, in <module>
TypeError: %d format: a number is required, not str

answered Dec 2, 2020 by vinita (108k points)

Please be informed that the '%d' is for decimal numbers in Python whereas the '%s' is for generic string or object and in the case of an object, it will get converted to a string type data.

Refer to the below code for reference:

name ='giacomo'

number = 4.3

print('%s %s %d %f %g' % (name, number, number, number, number))

The output:

giacomo 4.3 4 4.300000 4.3

As you can notice that the %d will truncate to integer, %s will maintain formatting, %f will print as float, and %g is used for generic number:

print('%d' % (name))

The above code will throw an exception as we cannot able to convert a string format data to number format data.

What is %s and %D used for?

%d – the argument is treated as an integer, and presented as a (signed) decimal number. %s – the argument is treated as and presented as a string.

How do you use %s %d in python?

In, Python %s and %d are used for formatting strings. %s acts a placeholder for a string while %d acts as a placeholder for a number. Their associated values are passed in via a tuple using the % operator. This code will print abc 2.

What does %s means in python?

%s specifically is used to perform concatenation of strings together. It allows us to format a value inside a string. It is used to incorporate another string within a string. It automatically provides type conversion from value to string.

How do you use %d and %f in python?

The formatting using % is similar to that of 'printf' in C programming language. %d – integer %f – float %s – string %x – hexadecimal %o – octal The below example describes the use of formatting using % in Python.

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