# zfill() Function in Python

zfill() Function in Python pads string on the left with zeros to the required width. We will be padding the integer or string with preceding zeros or leading zeros till the desired length is obtained using zfill() function.

#### Syntax of zfill() Function in Python

str.zfill(width)

width – width of the string.  The Final width which we would get after filling zeros.

#### Example of zfill() Function in Python

zfill() function takes up the string and fills the string  with preceding zeros until the desired length is obtained. we have shown two different examples below to depict the example of zfill() function in python.

```#zfill() for positive number string
number1="345"
print number1.zfill(4)

# zfill() for negative number string
number2="-675"
print number2.zfill(6)

```

so the output with preceding zeros filled will be

‘0345’
‘-00675’

#### Example of zfill() Function in Python for Text String:

In the  below example we will be using zfill() function to pad the text string to desired length.

```
##### zfill() for Text String

text="This is sample text"
text.zfill(40)

```

so the output with preceding zeros filled to the text will be

‘000000000000000000000This is sample text’

#### ALTERNATIVE METHOD TO zfill() function in python #### leading and trailing zeros using rjust() and ljust() function:

```

number1="345"
number1.rjust(7, '0')

number3="345.2"
number3.ljust(7, '0')

```

In the first example we are using rjust() function to add leading zeros to the string to the total length of 7. In the second example we are using ljust() function to add trailing zeros after the decimal until we get the total length of 7 digit. so the result will be

‘0000345’
‘345.200’

Format function takes up the numeric value as argument and pads them with preceding zeros until the desired length is reached. Here in our case we will padding till length 10.

```

number1 = 345
number2 = -675

#Method 1
'{:010}'.format(number1)
'{:010}'.format(number2)

```

so the result will be

‘0000000345’
‘-000000675’

Format function takes up the numeric value as argument and pads them with preceding zeros until the desired length is reached. Here in our case we will padding till length 7.

```

number1 = 345
number2 = -675

#Method 2
print(format(number1, '07'))
print(format(number2, '07'))

```

so the result will be

‘0000345’
‘-000675’