Inspired by https://github.com/jsvine/pdfplumber/issues/828
The PDF reference allows for "colors" to be defined as a series of
numbers and/or (much less commonly) patterns.
(See p. 288 and section 4.6 here:
https://ghostscript.com/~robin/pdf_reference17.pdf)
This commit separates out the pattern component of colors into their own
attributes, `stroking_pattern` and `non_stroking_pattern` so that they
don't muddle the interpretation of standard colors' tuple-of-numbers
representation.
This commit also adds code that attempts to fetch the `ncs`/`scs` color
space of each object. Due to current limitations of pdfminer.six,
however, the only such color space immediately available is the `ncs`
(non-stroking color space) property of char objects.
A fairly large commit, adding type annotations/hints to the entire
library, and refactoring the library accordingly.
Most of the refactoring changes should have no practical effect on
usage, but several others are notable:
- Added `TableSettings` class, a behind-the-scenes handler for managing
and validating table-extraction settings.
- Renamed the positional argument to `.to_csv(...)` and `.to_json(...)`
from `types` to `object_types`.
- Tweaked the output of `.to_json(...)` so that, if an object type is
not present for a given page, it has no key in the page's object
representation.
- Removed `utils.filter_objects(...)` and move the functionality to
within the `FilteredPage.objects` property calculation, the only part
of the library that used it.
- Removed code that sets `pdfminer.pdftypes.STRICT = True` and
`pdfminer.pdfinterp.STRICT = True`, since that [has now been the
default for a
while](https://github.com/pdfminer/pdfminer.six/commit/9439a3a31a347836aad1c1226168156125d9505f).
Per discussion at https://github.com/jsvine/pdfplumber/discussions/346
and input from @ramcdona, this commit changes pdfplumber's behavior
regarding floating point numbers. Specifically, it removes all
conversion of floats to Decimal objects. This brings several advantages:
- Increased precision (where applicable)
- Decreased code complexity
- Increased performance (~10% speedup on test suite)
- Increased fidelity to `pdfminer.six` output
These seem to outweigh the disadvantages:
- Some tests break (but have been easily fixed) due to increased
precision and/or floating point arithmetic artifacts
- Some users' scripts may also break, if they depend on strict equality
testing, though these *should* also be easily fixable
Because some form of automatic rounding may still be desirable for the
pdfplumber CLI utility, the conversion methods (.to_csv, .to_json) have
been adjusted to accept a `precision` argument.
See pdfminer.six's changelog for details:
https://github.com/pdfminer/pdfminer.six/blob/develop/CHANGELOG.md
... but a key difference is an improvement in how it assigns `line`,
`rect`, and `curve` objects. (Diagonal two-point lines, for instance,
are now `line` objects instead of `curve` objects.)
As a result, this commit also adjusts some of the tests, where the
pre-20211012 versions had been incorrectly assigning lines as `LTCurve`
objects.
This commit adds an `--laparams` flag to the pdfplumber CLI, giving it
more feature parity with the core library. To do so, it makes some
internal changes to `convert.py`, including changing the list of objects
to convert from *a predefined default list* to *all types extracted*.
Moves most of the logic previously in cli.py to convert.py, for usage by
other submodules. Adds Container.to_json and Container.to_csv. Makes
adjustments/fixes to other parts of the library, based on edge-cases
encountered (such as infinite recursion in anntations).
Jeremy Singer-Vine