200-901 Software Development and Design Practice Question

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✗

  for i, hostname in enumerate(hostnames): print(hostname)

  Why it's wrong here

  The `enumerate()` function returns both an index and the element, but the stem requires only processing each hostname, not tracking its position. The extra index variable `i` is unnecessary overhead for simple iteration. This structure is tempting because `enumerate()` is the correct choice when the loop body needs the index for operations like modifying the list in-place or correlating with a parallel list.

• ✗

  while len(hostnames) > 0: print(hostnames.pop())

  Why it's wrong here

  Popping from the list mutates hostnames, destroying the original data and skipping elements if the loop is re-entered; a for loop over the list iterates without side effects. It is tempting because while loops suit unknown iteration counts, and would be correct when consuming a queue until empty.

• ✗

  for i in range(len(hostnames)): print(hostnames[i])

  Why it's wrong here

  Indexing with range(len()) works but is unpythonic and obscures intent; iterating directly over hostnames is the idiomatic structure for processing each element. It is tempting because indices are needed when the position matters, which would make this the correct choice for tasks referencing element numbers.

• ✓

  for hostname in hostnames: print(hostname)

  Why this is correct

  A for loop iterates directly over the hostnames list, binding each element to the loop variable in turn, which is the idiomatic structure for processing every item in a sequence. It satisfies the requirement to process each hostname without manual index management.

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