Checking if all characters in a string are alphanumeric in Python

In data validation and string processing, the ability to ascertain whether all characters in a string are alphanumeric holds paramount importance. This thread describes two methods available in Python to perform this check, along with a sample code.

1. Using isalnum() method:

  • To check if a string contains only alphanumeric characters and not special characters, you can use the isalnum() method.
  • If the string consists solely of letters and numbers, this method will return True. Otherwise, it will return False.
  • Here is an example code which utilizes this method:

2. Using match() method:

  • An alternative method for checking if a string contains only alphanumeric characters is to use the match() method from the re (regular expression) module.
  • This method allows you to search for patterns within a string and can be used to check if the string consists only of letters and numbers.
  • To use this method, you will need to import the re module and write a regular expression that defines the pattern you want to search for in the string. Here is an example code: