10. Enumerate
enumerate() is a built-in function that pairs each element with its index. Its signature is:
iterable— the collection to walk through, such as a list or a string.start— the value of the first index. Default:0.- It returns pairs
(index, value), one per pass.
Unpack each pair into two names in the for header:
print(index, fruit) uses the default separator, so it prints 0 apple. To use a different layout, build an f-string: f"{index}: {fruit}".
Coming from JavaScript? enumerate(items) is items.entries(), but you unpack it directly in the loop header: for i, item in enumerate(items):.
Print index and value
Use letters = ["a", "b"]. Loop over enumerate(letters) and print the index and the letter in one print() call.
Print exactly:
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Format the index and value
Use letters = ["a", "b"]. Loop over enumerate(letters) and print index: letter using an f-string.
Print exactly:
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Start counting at one
Use letters = ["a", "b"]. Loop over enumerate(letters, start=1) and print the index and the letter in one print() call.
Print exactly:
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