How can I check if a string contains only ASCII letters and digits in Python?
Alex K

To check if a string contains only ASCII letters and digits in Python, you can use theisalnum() method and theord() function. Here's a long-form explanation of how to achieve this: 1. Check the string: - Iterate over each character in the string using a loop or a comprehension. - Use theord() function to obtain the Unicode code point of each character. - Theord() function returns an integer representing the Unicode code point of the character. - Compare the obtained code point with the ASCII ranges for letters and digits. - For ASCII letters, valid code points fall within the ranges of 65 to 90 (uppercase) and 97 to 122 (lowercase). - For ASCII digits, valid code points fall within the range of 48 to 57. - If the code point falls within these ranges, the character is either an ASCII letter or digit. - If any character in the string does not satisfy this condition, the string is not comprised only of ASCII letters and digits. - Example:

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def contains_only_ascii_letters_and_digits(string):
    return all(65 <= ord(char) <= 90 or 97 <= ord(char) <= 122 or 48 <= ord(char) <= 57 for char in string)

2. Use the function: - Call thecontains_only_ascii_letters_and_digits() function and pass the string you want to validate. - It will returnTrue if the string contains only ASCII letters and digits, andFalse otherwise. - Example:

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string = "Hello123"
if contains_only_ascii_letters_and_digits(string):
    print("Valid string")
else:
    print("Invalid string")

By using theord() function to obtain the Unicode code point of each character and checking if it falls within the appropriate ASCII ranges, you can efficiently validate if a string contains only ASCII letters and digits. This approach allows for concise and flexible validation based on the character's Unicode code point.

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