## Chapter 14 — Two labs are not one script ### Lesson map Lesson 14. Map, example, EX060. ```mermaid flowchart TD H["lab_hashcheck.py"] --> R1["Three filename rows"] S["lab_startup.py"] --> R2["Lengths and two NEW lines"] R1 --> N["Priya's note may sit beside both"] R2 --> N N --> Q{"Did either script print the other script's rows?"} Q -->|No| K["Keep the outputs apart"] ``` The note may place the results side by side. The files do not. ### Logical drawing ```text hash script sees three names and three byte strings startup script sees two sets of startup names neither script sees the other script's variables ``` ### Learning outcomes After this chapter, you should be able to: 1. Name the two scripts and their outputs. 2. Keep a prefix out of the startup print. 3. Refuse a merged lab that neither file produced. ### 14.1 Each file has its own names. The case note is a third page. `lab_hashcheck.py` walks a dict of filenames and byte strings. Its output is three rows: a prefix and either `no match` or the adware label. It never builds a set called `baseline`, and it never prints `NEW`. `lab_startup.py` walks two sets of startup names. Its output is a length line and two NEW lines. It never calls `hashlib`, and it never prints `0edf30e2fa30`, `3e5d3b83407c`, or `ffcab6e8630a`. Priya's notebook is allowed to mention both results in one paragraph, because she ran both checks and she labels the sources. That paragraph is not a third script. A sentence such as "the prefix caused AlertPopup" moves from two observations to a cause. The observations can sit together. The cause is not a column in either print. She also does not open the new programs. Their names, plus the hash label, are what she uses. There is no hidden third lab in this course. A classmate who pastes the prefix onto a NEW line has invented a tool. NIST's Computer Forensics Tool Testing program is how some forensic tools are examined. These two classroom scripts have not been submitted to it, and this chapter does not claim they were. | Script | Prints | Does not print | |---|---|---| | `lab_hashcheck.py` | Three filename rows | Startup names | | `lab_startup.py` | Lengths and NEW lines | Hex prefixes | | The notebook | Both, with sources | A fused column | ### 14.2 Worked example | Offered page | What it mixes | Decision | |---|---|---| | Hash print quoted alone | One script | Keep | | Startup print quoted alone | The other script | Keep | | "3e5d3b83407c NEW: AlertPopup" | A column neither file has | Refuse | | "One script printed both outputs." | Two files | Refuse | > **Synthetic case.** Two standard-library files, two embedded outputs. ### Errors and limits Do not weld the prefix to a startup name and call the weld a lab. ### Apply - **EX060 — Two outputs.** Can the startup print include `3e5d3b83407c`, and can the hash print include `NEW: AlertPopup`? *Rubric:* 3 = no; each script prints only its own rows; the notebook may cite both with sources; neither file contains the other file's columns;; 2 = the outputs stay separate;; 1 = one script;; 0 = none. ### Continue studying — lesson 14 (chapter 14 of 20) [← Chapter 13](#ch-13) · [Course chapter index](../SUBJECTS.md) · [Chapter 15 →](#ch-15) Continue to the next authored lesson. ## Worked answers **EX060.** No. The startup print has no prefix, and the hash print has no NEW line. The notebook may cite both with sources.