Add schema hinting to new sheets functionality (C4-1088)

[netsettler]

This is getting close to where it might be usable. Features available, including those which are available in some of the prevoius PRs. I've tried to highlight the areas of current development here:

• New module sheet_utils for loading workbooks.

  • Important things of interest:

  • Class ItemManager for loading Item-style data from any .xlsx, .csv or .tsv files. (Planned support, only partly implemented, for JSON via .json files and JSON LInes via .jsonl files.)

  • Function load_items that does the same as ItemManager.load. Features:

    • type hinting (see class TypeHint and its subclasses) to normalize/repair various kinds of inputs. Work ongoing in this area. Doug has requested this be done differently in various ways.

    • autoloading schemas based on tab names

    • object cross-references. Work on this "instaguid" feature is in flux and an area of ongoing work. Experimentation and considering of variations of implementations still planned before converging. WIll and Doug have asked questions. Kent plans a document soon itemizing alternatives and issues.

  • Various lower-level implementation classes such as:

  • Classes XlsxManager, CsvManager and TsvManager for loading raw data from .xlsx, .csv, and .tsv files, respectively.

  • Classes XlsxItemManager, CsvItemManager, and TsvItemManager for loading Item-style data from .xlsx, .csv, and .tsv files, respectively.

• New utility functionality in misc_utils:

  • New function is_uuid (migrated from Fourfront)
  • New function pad_to
  • New class JsonLinesReader

Still to do:

• Better doc strings
• Additional unit testing for coverage
• Redesign of instaguids after planned design discussion offline.
• Better framework for defining type hints. It would help to have input about kinds of transformations desired.

[coveralls]

Pull Request Test Coverage Report for Build 6157876570

• 636 of 718 (88.58%) changed or added relevant lines in 2 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.7%) to 78.464%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
dcicutils/misc_utils.py	35	38	92.11%
dcicutils/sheet_utils.py	601	680	88.38%
<!--	Total:	636	718	88.58%	-->

Totals
Change from base Build 6126356266:	0.7%
Covered Lines:	8890
Relevant Lines:	11330

---

💛 - Coveralls