## Chapter 5 — The lab print is list order ### Lesson map Lesson 05. Map, example, EX051. ```mermaid flowchart TD L["Six tuples, written order"] --> P["One pass, no sort"] P --> O["Six lines in that same order"] O --> Q{"Did severity pick the first line?"} Q -->|No| K["Keep the embedded print"] ``` The loop follows the list. It does not rank the rows. ### Logical drawing ```text e.finch Fri 08:52 UK ok e.finch Fri 13:05 UK ok e.finch Fri 23:47 BR CHECK: new country, night s.marlow Fri 09:10 UK ok l.barros Fri 08:30 UK ok e.finch Sat 00:02 BR CHECK: new country, night ``` ### Learning outcomes After this chapter, you should be able to: 1. Name the list the sign-in script walks. 2. Separate that written order from a severity ranking. 3. Refuse a note that reorders or drops a line. ### 5.1 One pass, and the format width is not a ranking. `lab_signins.py` stores six tuples. Each tuple is a user label, a day-and-time token, and a country token. Each pass takes the next sign-in tuple from `signins` and does not reorder the six. Nothing in the file calls `sort`, `sorted`, or `min`. The print format starts with `{user:9}`. Width 9 pads a short label with spaces on the right. `e.finch` is seven characters, so two pad spaces sit inside the field, and the format then adds one more space before the time token. `s.marlow` and `l.barros` are eight characters, so each keeps one pad space inside the field. Those spaces do not encode severity. Elaine's Friday 08:52 line is first because that tuple is first, even though a reader might want the Brazil lines moved to the top. The Saturday 00:02 line is last because that tuple is last, and it still prints. A later decision to investigate Elaine's mailbox is a sentence in the incident log. It does not delete a tuple. A print that started with the 23:47 line would be a different list. | What the loop uses | What it does not use | |---|---| | Position in `signins` | A severity score | | The three fields of that tuple | A mailbox search | | Format width 9 | A second ordering key | ### 5.2 Worked example | Offered result | What produced it | Decision | |---|---|---| | Six lines, Friday 08:52 first | List order, one pass | Keep | | Both Brazil lines still present | Their tuples were not deleted | Keep | | "The script sorted by country." | No sort is called | Refuse | | "The ok lines were dropped." | Four tuples still print `ok` | Refuse | > **Synthetic case.** These six tuples are the only sign-in output. ### Errors and limits Do not rebuild the list so that it matches a later investigation. ### Apply - **EX051 — List order.** The print names Friday 08:52, Friday 13:05, Friday 23:47, then `s.marlow`, `l.barros`, and Saturday 00:02. May a severity ranking, or a later decision to investigate one mailbox, replace that order? *Rubric:* 3 = no; the six tuples stay in written order; width 9 is padding; do not sort the script;; 2 = the six lines stay and the later decision stays prose;; 1 = one line;; 0 = none. ### Continue studying — lesson 05 (chapter 05 of 20) [← Chapter 04](#ch-04) · [Course chapter index](../SUBJECTS.md) · [Chapter 06 →](#ch-06) Continue to the next authored lesson. ## Worked answers **EX051.** No. The six tuples stay in written order. Width 9 only pads the label. A later investigation does not reorder the script.