Palindrome Check

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≈ 20 min · python-strings · Open in WolfCode

Two lines. Normalize first, then compare to the reverse. [::-1] is the standard reverse-slice idiom.

Python · runnable

def is_palindrome(text):
    clean = "".join(c.lower() for c in text if c.isalpha())
    return clean == clean[::-1]

for s in ["racecar", "Racecar", "A man, a plan, a canal: Panama", "hello", "", "Was it a car or a cat I saw?"]:
    print(f"{s!r:>40}: {is_palindrome(s)}")

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Normalizing — keep only letters

The build-from-chars idiom

text = "A man, a plan, a canal: Panama"
clean = "".join(c.lower() for c in text if c.isalpha())
print(clean)
# "amanaplanacanalpanama"
print(clean == clean[::-1])
# True

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