PCAP Exceptions and File I/O 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.

• ✓

  Step 1: Import the json module. Step 2: Create a Python dictionary. Step 3: Open a file in write mode. Step 4: Use json.dump() to write the dictionary to the file.

  Why this is correct

  This sequence is correct because the json module must be imported before any of its functions, such as json.dump(), can be referenced. The Python dictionary must then exist as the data to be serialized, followed by opening a file in write mode to provide a writable file-like object. Only after the file is successfully opened can json.dump() be called, as it writes the serialized JSON directly to that open handle. Attempting to run json.dump() without an open file would raise a TypeError or AttributeError, so the given order ensures every dependency is satisfied before the critical call.

• ✗

  Step 1: Create a Python dictionary. Step 2: Import the json module. Step 3: Open a file in write mode. Step 4: Use json.dump() to write the dictionary to the file.

  Why it's wrong here

  This is incorrect because importing the module should be done before any other operations to ensure the module is available; creating the dictionary first is not a syntax error but is not the conventional order.

• ✗

  Step 1: Import the json module. Step 2: Open a file in write mode. Step 3: Create a Python dictionary. Step 4: Use json.dump() to write the dictionary to the file.

  Why it's wrong here

  This is incorrect because you need to have the dictionary object ready before calling json.dump(); opening the file before creating the object is not logically wrong but is not the typical sequence and could lead to confusion.

• ✗

  Step 1: Import the json module. Step 2: Create a Python dictionary. Step 3: Use json.dump() to write the dictionary to the file. Step 4: Open a file in write mode.

  Why it's wrong here

  This order is invalid because json.dump() is called before the target file is opened, even though the file is opened afterward. At the time json.dump() executes, the variable intended to hold the file object either does not exist (causing a NameError) or refers to something that is not a writable file (causing a TypeError). Opening the file after the dump call cannot retroactively provide the required writable stream, so serialization fails outright. The correct approach is to open the file in write mode first, then pass that open file object as the second argument to json.dump().