If we are using any integer then we have to convert the same to string by using str() before using. Here is the error message
AttributeError: 'int' object has no attribute 'zfill'
id=str(45) #convert to string
print(id.zfill(5)) # 00045
It works only with strings, so integers must be converted to strings before using zfill(). This is helpful when handling numerical IDs or fixed-length formats.
Employee numbers need to be formatted as five-digit, auto-incremented values, starting with leading zeros for smaller numbers. Using zfill(5) ensures this formatting.
For example, early employee IDs like 5, 78, and 147 will appear as 00005, 00078, and 00147, while later ones like 1587 and 11258 will naturally appear as 01587 and 11258. This guarantees a consistent 5-digit format across all employee numbers.
The zfill() method makes it simple to enforce this padding for uniform ID lengths. « All String methods