Compare parsing with pattern matching
See this course’s project requirements
A checked extraction script for fictional equipment tags, dates and log lines, with a mismatch report and exact-match safety boundaries.
Keep your working files in your own notebook or software. Save a private description, checklist, and work link in My Proof.
What to include
- A precise tag grammar with four checked cases.
- A segment-by-segment match explanation.
- A whole-input validation rule with a counterexample.
- An extracted log record with explicit string/number distinctions.
- A semantic date check separate from regex matching.
- A tested tag-and-log extraction tool with semantic limits.
Review and revise
Use these criteria to check your work and choose what to improve.
- The implementation or declared simulation follows the supplied contract and retains inspectable original inputs.
- Normal, boundary and rejected cases are recorded with expected versus observed results.
- The changed case has a correct explanation and does not rely on hidden state.
- The project includes source, outputs, instructions and honest tool, privacy and verification limits.
Want more background?
The idea in everyday life
EQ-123 2026-02-30 ready matches the digit-and-hyphen shape, but February 30 is not a valid calendar date.
A regular expression can accept a date-shaped string that is not a real calendar date. After shape validation, use date.fromisoformat for calendar meaning and preserve its rejection.
Compare parsing with pattern matching — original worked practice
A regular expression can accept a date-shaped string that is not a real calendar date. After shape validation, use date.fromisoformat for calendar meaning and preserve its rejection.
EQ-123 2026-02-30 ready matches the digit-and-hyphen shape, but February 30 is not a valid calendar date.
1. Step 1
Match the line shape first.
You should see: All field positions fit the pattern.
This keeps the rule and its observable result together.
2. Step 2
Pass day to date.fromisoformat.
You should see: ValueError rejects February 30.
This keeps the rule and its observable result together.
3. Step 3
Compare valid 2026-02-28.
You should see: The parser accepts it.
This keeps the rule and its observable result together.
4. Step 4
Write a two-stage shape-plus-meaning decision.
You should see: A semantic date check separate from regex matching.
This keeps the rule and its observable result together.
What to finish
A semantic date check separate from regex matching.
Watch for this
Treating a date-shaped string as proof that the calendar date actually exists.
How can I tell I understand it?
Explain and demonstrate the required distinction: A regular expression can accept a date-shaped string that is not a real calendar date. After shape validation, use date.fromisoformat for calendar meaning and preserve its rejection. Show a changed input and the expected result without weakening this contract.
Quick knowledge check
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Sources and further reading
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Source & access notes · checked 2026-10-01
Relevant documented module/API behavior inspected during expansion authoring; actual execution evidence is recorded separately. No grant eligibility is established.
Access: Official page retrieved with the web reader on 2026-10-01. Documentation reading does not certify execution in every native tool or browser.
Reuse: Original local practice files, fictional data, worked examples and questions. Concepts paraphrased and linked; source exercises are not copied.
Source & access notes · checked 2026-10-01
Relevant documented module/API behavior inspected during expansion authoring; actual execution evidence is recorded separately. No grant eligibility is established.
Access: Official page retrieved with the web reader on 2026-10-01. Documentation reading does not certify execution in every native tool or browser.
Reuse: Original local practice files, fictional data, worked examples and questions. Concepts paraphrased and linked; source exercises are not copied.
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