WKTWriter with trim=True and rounding_precision=N misbehaves

Hi,

I might discovered a suspicious behavior of the WKTWriter.

I did test with the following Point:

from shapely.wkt import dumps
from shapely.geometry import Point

p = Point(527626.9300000001, 0.00)

“dumps” the point with the “trim=True” should remove trailing zeros (it happens).

print(dumps(p, trim=True))

POINT (527626.9300000001 0)

“dumps” the point with the “rounding_precision=4” round the point to 4 decimal places. In this case it removes 000001 from X coordinate and adds 00 to Y coordinate (it happens).

print(dumps(p, rounding_precision=4))

POINT (527626.9300 0.0000)

The potential error happens when both trim=True" and “rounding_precision=4” are applied to the point. It seems to me that the coordinates are converted to a scientific notation on which the rounding_precision is applied.

print(dumps(p, trim=True, rounding_precision=4))

POINT (5.276e+05 0)

I did tests on both Windows and Linux operating systems.

[mwtoews]

FYI, this may potentially change with GEOS 3.10 (or current master), which uses Ryū (via https://github.com/libgeos/geos/commit/2376cd6bf5d0743b02b588af17d2e9067c1874de) for string formatting/rounding stuff.

[sgillies]

Let’s close this one and reopen if it’s still a problem with GEOS 3.9.