Python String zfill() Method

By Yash Ramani

In this tutorial, we will learn zfill() method in Python with some examples.

zfill() means “Zero Fill”. The string zfill() method of Python returns a copy of the string with ‘0’ characters padded to the left of the string. It simply means that it will add no. of zero’s in your string with a defined width.

Syntax :

str.zfill(width)

Where width is the length of the String.

Now see some of the examples of using the Python zfill() method:

1. In the first example which has a width greater than the string length.  It gives a new string containing 0 from left and is equals to width.

   num = "125"
   
   str1 = num.zfill(10)
   
   print(str1)
   

   OUTPUT:
   0000000125

   • We take a number string like “125” and have a width “10”. So that it will give zero’s from the left and then write number string.
2. In the second, we declared width is less than string length. So it gives string as output.

   txt = "I love Pyhton"
   
   str2 = txt.zfill(5)
   
   print(str2)
   
   

   OUTPUT:
   I love Python

   •  We have to take a normal string or line and its length is less than the width of zfill(). So it will see as a normal string only.
3. In this, we can use + or – and any decimal number to a string. It describes + or – includes before the zero fills to the left of our string. As you can see below, every value is filled after prefixing (+ or -) sign.

   val1 = "+100"
   val2 = "-500"
   val3 = "20.00"
   
   str3 = val1.zfill(15)
   str4 = val2.zfill(15)
   str5 = val3.zfill(15)
   
   print(str3)
   print(str4)
   print(str5)

   OUTPUT:
   +00000000000100
   -00000000000500
   000000000020.00

• •  We have taken 3 different numbers as “+”,”-” and “decimal” respectively and given zfiil() method each. So they will be printed as operator and then zero’s from the left.

Also Read: Generate Random Number String in Python