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Exercise 8

Explain why the code below prints different values on lines 3 and 4.

text = "It's probably pining for the fjords!"

print(text[21:35].rfind('f'))     # 8
print(text.rfind('f', 21, 35))    # 29

Solution

Line 3 first extracts a slice from text ranging from index 21 through index 35. That returns the string 'for the fjords'. rfind then returns 8, the index of the rightmost instance of an 'f'.

On the other hand, line 4 does a search for the rightmost f between indexes 21 and 35. Since the f occurs at index 29, that's what the method returns.

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