QUESTION 268 What is the expected behavior of the following program? foo = (1, 2, 3) foo.index(0)

Question

Options

• AThe program will cause a AttributeError exception.
• BThe program will cause a SyntaxError exception.
• CThe program will output 1 to the screen.
• DThe program will cause a ValueError exception.
• EThe program will cause a TypeError exception.

• A
  2% (1)
• B
  5% (3)
• C
  2% (1)
• D
  83% (50)
• E
  8% (5)

Explanation

Calling foo.index(0) on the tuple (1, 2, 3) raises a ValueError because the value 0 does not exist in the tuple - index() throws ValueError whenever the searched value is absent, just as it does for lists.

Why distractors are wrong:

• A (AttributeError): Tuples do have an .index() method, so no AttributeError occurs - it's a valid tuple method.
• B (SyntaxError): The code is syntactically valid Python; a SyntaxError only occurs when the code itself is malformed (missing colons, mismatched brackets, etc.).
• C (output 1): Even if 0 were in the tuple, .index() returns the integer index position silently - it doesn't print anything, and 0 isn't there regardless.
• E (TypeError): A TypeError would occur if you passed an incompatible type to the method (e.g., wrong number of arguments), but an integer argument is perfectly valid here.

Memory tip: Think "ValueError = the Value you asked for can't be found." Whenever a search method (.index(), .remove()) can't locate the target value in a sequence, Python raises ValueError - not an attribute or type error, because the method and type are both correct.

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