Create a list of characters that are not alphanumeric from a string
This Python code takes a string, iterates through its characters, and creates a new list called non_alphanumeric containing characters that are not alphanumeric (neither letters nor numbers). Here's how the code works:
- string = "Hello, world!": This line initializes a variable named string and assigns it the value "Hello, world!".
- non_alphanumeric = [char for char in string if not char.isalnum()]: This line of code initializes a variable named non_alphanumeric and assigns it the result of a list comprehension.
- for char in string: This part sets up a loop that iterates through each character char in the string.
- if not char.isalnum(): This is a condition that checks whether the current character char is not alphanumeric. The char.isalnum() method returns True if char is an alphanumeric character (a letter or a number) and False otherwise. The not keyword negates this condition, so it selects characters that are not alphanumeric.
- [char for char in string if not char.isalnum()]: This is the list comprehension itself. It iterates through the characters in the string, includes only those characters that are not alphanumeric, and includes them in the new list.
- print(string): This line of code prints the original string to the console.
- print(non_alphanumeric): This line of code prints the non_alphanumeric list to the console.
Source Code
string = "Hello, world!"
non_alphanumeric = [char for char in string if not char.isalnum()]
print(string)
print(non_alphanumeric)
Output
Hello, world!
[',', ' ', '!']